What qwen3.8-flash-next did

Let me look at the working directory first.

Let me plan the design carefully.

Key design: tile 8 logical px, viewport 16×16 tiles = 128×128 logical px, scaled up (e.g., 4x or 5x → 512 or 640). Level height = 16 tiles. Width: several screens wide, say 40 tiles (2.5 screens) or 48 tiles (3 screens). Let's do 56 tiles wide? Let's design carefully.

Let me design the level as a string array of 16 rows.

Legend:
- `#` solid block
- `^` spike
- `o` hoop
- `c` checkpoint
- `C` crystal ball
- `E` exit door (2 tiles tall) — mark two cells with `e` maybe, top and bottom.
- `.` empty
- `@` spawn

Physics: gravity 22 t/s², bounce height 3 tiles → v = sqrt(2*22*3) = sqrt(132) ≈ 11.489 t/s. Terminal fall 14 t/s.

Air time for a full bounce from flat: time up = v/g = 0.522s, total ~1.045s. At max roll speed 6 t/s, horizontal distance per hop ≈ 6.3 tiles. Hmm, but landing while holding bounce — the ball leaves ground again immediately. So max gap crossed ≈ 6 tiles at full speed. But a gap must be clearable with a single bounce: a gap of ~3 tiles is comfortable from standing? From standing, jump height 3 tiles gives horizontal distance depending on speed. Hmm — from standing, holding bounce launches vertically only, no horizontal. So crossing a gap requires horizontal speed at launch. Gap of 3 tiles: need v_x * 1.045 ≥ 3 → v_x ≥ 2.87 t/s, easily attained with run-up of ~0.16s... acceleration 18 t/s², so 2.87 t/s in 0.16s over 0.23 tiles. Very easy. Good — be generous, gap of 3 tiles is fine, maybe 4 tiles still fine (v_x ≥ 3.83).

Height of wall clearable from standing: 3 tiles bounce height means the ball can rise 3 tiles. Ball is 1 tile diameter. To land on top of a wall of height h (measured in tiles from floor the ball stands on): the ball's bottom must reach h tiles above. Bounce height 3 tiles measured as center rise presumably — apex of the ball's position. Rise of 3 tiles means the ball's bottom clears a 3-tile-high wall exactly at apex? Actually to land on top of a 3-tile wall, the ball's bottom needs to reach exactly the top surface of the wall = 3 tiles above the current floor. That's exactly at apex — too tight. Use max 2-tile walls for comfort, maybe a 3-tile wall only where the landing is forgiving... Actually careful: bounce height 3.0 tiles — I'll define the launch speed so apex is 3.0 tiles above launch position. Landing on a wall 2 tiles high: ball reaches that height with plenty of margin — with 22 t/s², reaching 2 tiles needs v = sqrt(2*22*2)=13.26... wait that exceeds launch speed 11.49. Hmm: apex height h = v²/(2g) = 132/44 = 3. Yes. To reach a rise of 2 tiles, need v ≥ sqrt(2*22*2) = 13.26? That's wrong: v²/(2g) = 2 → v = sqrt(2*2*22) = sqrt(88) = 9.38. Right, sqrt(2*g*h). Fine, 11.49 > 9.38. Good. So a 2-tile wall is cleared with margin: at rise of 2 tiles, remaining vertical speed = sqrt(132-88)=6.6 t/s, so it has margin. Time to apex 0.522 s.

Practical: rising onto a ledge of height 2 while moving at 6 t/s: horizontal distance during the rise ~ let's compute time when y-rise = 2 going up: t = (v - sqrt(v²-2g*2))/g = (11.489-6.633)/22 = 0.22s. So it passes the ledge top at 0.22 s and keeps rising until 0.522s, staying above 2 tiles height for 0.6s → 3.6 tiles of horizontal travel at 6 t/s. Fine.

Design with ledges max 2 tiles.

Now let's plan the level. Width: let's use 64 tiles (4 screens) — gives room to pace it. Level height exactly 16.

Let me lay out a coordinate system: x from 0 to 63, y from 0 (top) to 15 (bottom). Ground rows typically y=14,15 solid in the opening; let's think about vertical space.

Let me draft the level in segments.

Segment A (x 0–11): Open ground, safe. Spawn at x=2, y=12 (feet on y=13? Let's define ground top surface at row 13, i.e., rows 13,14,15 solid). Spawn ball at x=2.5 tiles, y feet at 13.

Hoop 1 at x=6, y=12 (floating just above ground, easy grab by rolling or a small bounce). Hoop 2 at x=10, y=9 — requires bounce (3 tiles up from ground: ball bottom rises 3, so ball center at ... a hoop at y=10 reachable). Let me think: standing on ground surface y=13 (top of solid row 13 means ball rests occupying row 12). Ball center at y=12.5 (in tile coords, center). Bounce apex raises center by 3 → 9.5, so ball occupies rows ~9. Hoops collected on overlap (ball circle overlapping hoop's region) — a hoop at row 10 will be touched during the rise. Good.

Segment B (x 12–23): first walls. A 2-tile wall (blocks at rows 11,12 above ground top 13 → wall of height 2 tiles: rows 11 and 12 solid, meaning surface top at row 11, ball must land on top... Actually a "wall" the player bounces over. Let's have a wall of 2 solid rows sitting on the ground: rows 11,12 at x=14 (ground rows 13-15). Ball must bounce to clear it: top of wall at y=11 (its top surface). Ball's bottom must reach y=13 i.e. rise of 2 tiles? Ball standing on ground with bottom at y=13.0 (top of row 13 = boundary y=13). Wall top surface at y=11 (top of row 11). Rise needed = 2 tiles. OK, doable with margin.

Then a second, taller... keep max 2. Maybe a two-step staircase: wall 1 at x=17 height 1, then platform height 2 at x=20.

Hoop 3 in this segment, e.g. on top of a ledge.

Checkpoint 1 at x≈23 (before the gap section).

Segment C (x 24–35): the gap in the floor, floored with spikes. Ground drops: rows 13–15 become empty at x=26..30 with spikes at the bottom row (y=15) filling... "The one gap in the floor is floored with spikes rather than bottomless." So gap of e.g. 4 tiles wide, with spikes on the floor of the gap (row 15 or the pit bottom). Let's make a pit: at x=26..29 the top ground rows (13) are missing, pit floor at row 15 with spikes there. Depth: falling in = death, but escapable (can bounce out? From pit floor row 15 top = y=15, ball occupies row 14; bounce rise 3 → up to y=11... needs to get onto ground surface at y=13 — yes, 2-tile rise, escapable but must land on the edge). Hmm but if you fall in the pit and there are spikes at row 15, you die instantly. Let's rather: pit has spikes covering only part of the pit floor, with a safe landing spot in the middle so it's escapable (spec says every area is escapable). Better: gap of 3 tiles wide, spikes on the bottom row across the gap (row 15), and the pit is 2 tiles deep on the sides... hmm.

Simpler and safe: floor gap where the tiles below are spikes at the very bottom of the gap (row 15) with solid at rows... Let's set: main ground rows 14,15 solid throughout the level (as a base floor), and the "gap" is a pit where an extra ground layer... Hmm, the level is 16 tall; let's define:

Base terrain: rows 14 and 15 are solid everywhere (bedrock) except in the pit where row 15 becomes spike tiles. The walking surface in open areas is row 14 top (i.e., floor surface at y=14). Hmm, but then a "gap in the floor" means the pit is at row 14 only with spikes at row 15 — a shallow 1-tile-deep hole with spikes. Falling in = spike death (spike hitbox smaller region inside tile). Escapable: bounce from pit floor (surface top y=15) rise 3 → clears back to y=14 surface easily. But if you land in the pit you might sit on spikes and die — fine, it's the hazard. The spec says the gap is floored with spikes rather than bottomless — good, and the escape rule: "Every area is escapable, and a respawn never places the ball inside a solid or a hazard." Checkpoint respawn is on solid ground, fine.

But a shallow 1-tile spike pit you can just walk over? No — walking into a spike tile kills. Actually the ball must jump it. Make the spike gap 3 tiles wide with a small solid island in the middle? The spec: gap in the floor floored with spikes. And "hazard sequence" later. Let me design:

Segment C (x 24–37): gap crossing. Ground row 14 solid up to x=27; from x=28 to x=33, row 14 is empty (a real gap 6 tiles? too much). Hmm let's reconsider: make a pit that's 2 tiles deep (rows 13, 14 missing at those x), floor row 15 solid, with a few spike tiles on the pit floor (row 15 top surface). Crossing: bounce across. Full-speed hop distance ≈ 6.2 tiles; a 4-tile gap at moderate speed works. Give landing room on both sides.

Actually simplest coherent design: define the ground surface at two levels. Main floor surface level: top of row 14 (y=14). Pit: at x=28..32 the rows 13,14 removed → pit floor is row 15 top (y=15), only 1 tile deeper. Spikes placed on row 14? Hmm.

Let me reconsider with a clear picture. I'll write the map as 16 rows of text and just carefully design it visually. Let's do that. 64 columns.

Let me define column ranges:
- 0–2: starting area wall on left (solid column x=0 rows 0..15? Better a wall to prevent leaving; collisions clamp to world bounds anyway. Let's have solid border on left and right columns, and top? Top open is fine but clamp ball to world bounds in code regardless.)

Rows (y): 0 = top.

Design draft (64 wide):

Ground: rows 13,14,15 solid in most of the level → walking surface top y=13.
Ceiling/overhangs: a few blocks at rows 9-11 for the crystal ledge.

Let me write out row strings per column. I'll construct programmatically in my head with segments.

Let me build a helper mentally: each row is a string of 64 chars.

I'll define column-by-column heights. Ground heights (top solid row) per column segment:

x 0: solid all rows (left border).
x 1–11: ground top = 13 (rows 13,14,15 solid).
x 12–13: ground top = 13.
x 14: pillar rows 11,12 solid (wall height 2 on top of ground) → top = 11.
x 15–16: ground top = 13.
x 17: pillar rows 12 solid (wall height 1) → hmm.

Better make a sequence of walls to hop: at x=14 a 2-tall wall; x=18 a 2-tall wall; then a ledge/steps.

Let me instead make a "staircase" with the crystal ledge above.

I'll do a concrete ASCII draft. Let me pick width 60 tiles (3.75 screens) — camera shows 16 wide. Actually let's do 64 for roundness.

Here's my plan by segment:

**Segment 1 — Learning ground (x 0–13)**
- Ground rows 13–15 solid.
- Hoop 1 at (x=6, y=12) — collect by rolling/bouncing.
- Hoop 2 at (x=10, y=10) — must bounce (3-tile rise from ground gets ball center to 9.5; passing through y=10 on the way up). Good.
- Left border wall at x=0 (rows 0–15 solid).

**Segment 2 — Walls (x 14–25)**
- Wall A: x=15, rows 11–12 solid (2 tall) — bounce over from standing.
- Hoop 3 at (x=18, y=10) — bounce.
- Wall B: x=20, rows 11–12 solid.
- Steps: x=23 rows 12 solid (1 tall step), x=24 rows 11,12 solid (2 tall)... careful: a step sequence where you have to climb: from ground (top y=13), step of 1 tall at x=23 (top y=12): can you get on a 1-tall step by bouncing? Yes, rise of 1 needed.
- Checkpoint 1 at (x=26, y=12) on the ground surface (top y=13), before the hazard/gap section.

Hmm, need ground continuous at x=26. Let's simplify: keep the ground surface at y=13 for segments 1–3 and use obstacles on top.

**Segment 3 — The gap (x 27–38)**
- Ground (rows 13,14) ends at x=29. From x=30 to x=33, rows 13,14 are missing → pit with row 15 present as pit floor? If row 15 is present, the pit floor top is y=15, which is 2 tiles below the walking surface y=13. Falling in is survivable (no spikes on part) and you can bounce out (rise of 2 needed, bounce gives 3). Put spikes at the pit floor for x=31,32 (row 15 top at y=15) and leave x=30 and x=33 pit floor safe → escapable and a fair punishment.
- Gap width for jumping: 4 tiles (x=30..33). Landing on the other side at x=34 where ground surface resumes at y=13.
- Actually make it interesting: a small platform in the middle? "no moving enemies" but static platforms fine. Let's keep the middle pit: put a solid block in the pit? Keep it simple.
- Hoop 4 across the gap at (x=36, y=12) easy, or over the gap at (x=31, y=11)? Collecting a hoop mid-air over the gap requires a full-height bounce — fun but risky. Better place hoop 4 on the far side, safe: (x=36, y=10) requiring bounce.
- Checkpoint 1 before the gap at (x=28, y=12) — good: banks progress before the two hardest stretches (gap + hazard sequence). Hmm spec: "The two checkpoints bank progress in front of the two hardest stretches." So CP1 before the gap, CP2 before the final hazard gauntlet.

**Segment 4 — Hazard sequence (x 39–52)**
- Ground surface y=13 continues.
- Spike tiles on the ground: at x=41 (spike sitting on ground, occupying row 12), x=45, x=48... spaced generously (4+ tiles apart) with clear landing room.
- Hoop 5 at (x=43, y=10) requiring a bounce over a spike and collecting mid-air.
- Crystal: high ledge above — e.g. platform of solid blocks at rows 8, x=44–46, with the crystal on top at (x=45, y=7). Reaching a platform at row 8 top = y=8: from ground y=13, need rise of 5 — too high. Need intermediate ledges: ledge at row 11 (rise 2) above a spike area? Detour: side alcove instead.

Let's design crystal as a side alcove: a raised platform accessible from a lower step, requiring two bounces, off the critical path. E.g., near segment 3/4: a tower on the top area reachable by steps at x=19–22 with the crystal at the top. But "off the critical path" and "deliberate detour" — could also be behind you: you pass it and must go back, or it's above a spike pit — dangerous and optional. Nice design: crystal sits on a ledge above the spike sequence, reachable by a 2-step climb, and landing on it means you must then drop back down. Let's place it in segment 4 but make the climb optional and slightly risky.

Actually cleaner: put the crystal high above the pit gap section — an overhang ledge with crystal, reachable by bouncing off a mid-air-height ledge? Two-step: a small solid pedestal at ground level near x=27 (1 tall), then a ledge at rows 10 above the gap... Hmm rising 3 per bounce; from pedestal top y=12 to ledge top y=10 = rise 2, fine.

Let me do: crystal ledge at rows 9 solid at x=31–33 (above the pit at height 9 top y=9) — reachable? From the pit floor (top y=15) rise 3 → y=12, not enough. From ground surface y=13 → apex y=10, ball bottom reaches y=10... to land on a ledge whose top surface is y=9, need rise of 4. No.

OK do a two-step climb on the far side of the gap:
- Solid step block at x=36, rows 12 (1 tall) → top y=12.
- Ledge at x=38–40, rows 10 solid → top y=10. From step top y=12 rise needed 2 ✓. But is the step in the critical path? x=36 is on the ground path; stepping onto it blocks? A 1-tall block in the middle of the path — you'd have to hop it (rise 1, trivial). Fine.
- Crystal at (x=39, y=9) on top of that ledge.
- Then from the ledge, continue: drop down to the right onto ground at x=42.

Hmm, but then that ledge is on the critical path effectively. "Off the critical path" — the crystal just must not be required; having the ledge as an optional climb is fine if the ground route continues below. But a block at x=36 on the path... make the step block at x=36 be off the path? Ground at x=34..41 continuous, and step at x=36 rows 12 solid is an obstacle you can hop. Alternatively climb via a 2-step tower: x=38 rows 12 solid and x=39? Blocks can't stack as "steps" adjacent...

Let me restructure: place a tower with steps going up on the left of the ledge:
- step1: x=36, rows 12 solid (top y=12, rise 1 from ground y=13)
- step2: x=38, rows 11,12 solid (top y=11, rise 1 from step1 top y=12; but step1 at x=36 and step2 at x=38 with a 1-tile gap at x=37 — the ball must hop from step1 to step2: gap 1 tile, rise 1: easy with a bounce)
- ledge: x=40–42, rows 9 solid, top y=9. From step2 top y=11 rise 2 ✓. Horizontal gap x=39 (1 tile) between step2 and ledge ✓.
- Crystal at (x=41, y=8) on the ledge.
- Below the ledge at x=40–42 ground level: safe ground to pass under (rows 13–15 solid, plenty of headroom: ledge bottom at y=10, ground surface y=13 → 3 tiles of clearance: ball is 1 tile; fine).

Then continue the critical path on the ground. The detour: hop up the steps, grab the crystal (+1000, +1 life), drop back. Good — clearly optional and a "deliberate detour".

**Segment 5 — Final gauntlet (x 43–63) hardest**
- Spike cluster with tight but fair spacing, hoops, and the exit door.
- Exit door at x=61 (2 tiles tall: rows 11,12 above ground y=13). Door frame maybe solid around.
- Hoop 6 before the exit at (x=58, y=10) — must bounce.
- Checkpoint 2 at (x=44, y=12) before the gauntlet.

Let me now place spikes thoughtfully, with "several clear tiles between spikes and after every landing".

Spikes on the ground: each spike occupies one tile (row 12, sitting on ground row 13) but lethal hitbox smaller region inside.

Spike sequence idea: spikes at x=47, x=50, x=53 — 3 apart. Bouncing over one spike at moderate speed: from a full bounce the ball is airborne ~1.05 s covering up to 6 tiles; so you can clear 2–3 spikes in one hop, or hop individually. Spacing 3 tiles: after clearing spike at x=47, you land somewhere in x=48..49 region, next at 50. Landing room ~2 tiles. Hmm "several clear tiles between spikes and after every landing". Let's space them 4 apart: x=47, 51, 55. And the last stretch should be hardest: e.g., a spike pair at x=57,58 adjacent (2-wide spike patch) requiring a committed jump with a run-up, landing at x=59+ clear, then exit at 61-62.

Hmm, careful: a 2-wide spike patch: from standing, jump distance is 0 (no horizontal). To clear a 2-wide patch you need horizontal speed at launch. Standing next to the patch: takeoff at x=56.5 (ball diameter 1) needs to land past x=58+... distance ~2.5 tiles at some speed: v_x ≥ 2.5/1.045 = 2.4 t/s. Easy to get speed; and rolling into it costs lives. It's fine but let's keep it generous: max 2-wide spike patches.

Also spikes in the pit (x=31,32 on row 15).

Now let's verify hoop count = 6, checkpoints = 2, crystal = 1, exit = 1 (2 tiles).

Hoops: (6,12), (10,10), (18,10), (36,10)... let me recount with the final layout. I'll finalize the map now.

Let me settle: ground top row = 13 (rows 13,14,15 solid) for x=1..59 except the pit x=30..33 (rows 13,14 removed; row 15 spikes at x=31,32; row 15 solid at x=30,33? Wait if row 15 is spikes at 31-32 and solid at 30,33, and rows 13,14 removed at x=30..33 — the pit floor is at y=15 with spikes covering the middle. Falling in the pit: you'd land on either solid floor at x=30/33 (safe, bounce out: rise 2 needed from y=15 to y=13 ✓ since bounce = 3) or spike at 31/32 (death). Good: escapable, punished.

Hmm, but wait: at x=29 the ground top is row 13, meaning rows 13,14,15 solid; at x=30 rows 13,14 are empty but row 15 solid. So the pit is a 2-tile-deep notch. The ball rolling off at x=29 drops 2 tiles onto the pit floor. Fine.

Gap jump: from x=29 edge to x=34 ground edge = horizontal span of 5 tiles (x=30..34? Let's count: standing at x=29 (top y=13), jump onto x=34 top y=13 — the ball needs to travel from ~x=28.5 to x=34 → ~5 tiles horizontally while staying above y=13 the whole time. At v_x = 6 t/s, air time 1.045 s → 6.27 tiles. It's doable at near-max speed but that's tight-ish for a "not frame-perfect" requirement — you need ≥4.8 t/s and to launch right at the edge. Hmm, that's speed-demanding. Reduce the gap to 3 tiles: pit at x=30,31,32 → land at x=33. Distance from takeoff (ball center x ≈ 28.9 if ball at edge) to landing x ≥ 33 → ~4.2 tiles at 6 t/s = 0.7 s of the 1.05 s flight. Comfortable. Also the player could fall in and bounce out.

Hmm, but if the pit floor is only 1 tile lower than the surrounding ground (pit floor top y=15 vs ground top y=13 — that's 2 tiles lower), wait: pit rows 13,14 removed → pit floor surface = top of row 15 = y=15, which is 2 below y=13. Yes 2 tiles.

Let me make the pit x=30..32 (3 wide) and make the far edge at x=33 solid ground. Spikes on pit floor: x=30,31,32 all spikes (row 15)? Then falling in always kills, which is fine (it's the hazard) but "every area is escapable" — a lethal pit isn't escapable... It says every area is escapable. To be safe: make pit floor spikes at x=30,31 and solid at 32? Then if you land at x=32 you're safe and can bounce out. Actually falling in is a death trap only where spikes are. Let's do: pit x=30..32, row 15 = spike at x=30,31; solid at x=32 — landing on the small solid shelf at the far end of the pit is safe and you bounce out (rise 2 from y=15 to y=13 — the ball must clear the 2-tall wall at x=33 rows 13,14 — bounce gives 3 ✓). Good, escapable.

Hmm wait, from pit floor at x=32 (ball occupies row 14, center y=14.5), bounce rise 3 → center to 11.5, ball bottom at 11 → clears y=13 top surface of row 13 at x=33? The ball needs its bottom above y=13 when moving horizontally to x=33. It has plenty of time. ✓

Now the final stretch. Let me place:
- Ground rows 13–15 solid from x=33 to x=59.
- Right border: x=60..? Let's say exit door at x=61,62... Level width 64: columns 0..63. Let's set ground to x=62 and border wall at x=63 (solid all rows). Exit door occupies x=61, rows 11 and 12 (2 tiles tall, sitting on ground top y=13). Behind/around the door: solid column x=62 rows 11,12? To make the door "impassable while closed" — physically, when closed, treat door tiles as solid; when open, passable and touching completes the level.

Let's put a wall behind the door: x=62 solid rows 0..12? Hmm — actually make the exit a niche: column x=62 solid from row 0 to row 12 (a cliff), and the door at x=61 rows 11,12 embedded in the cliff face. When closed, the door tiles are solid → wall; the player must open. When open, walking into the door tile completes. Fine.

Final gauntlet design (x=43 → 60):
- Checkpoint 2 at (x=44, y=12) — on the ground, before the hardest stretch.
- Spikes: at x=48, x=52, x=55, then a pair x=56,57? Careful about landing zones: after jumping x=56,57 patch you land at x≥58 with the door at 61 — generous.

Hmm, let me reconsider spacing to be generous but rising difficulty:
- spike at x=48 (single)
- spike at x=52 (single)
- spikes at x=55,56 (pair)
- clear x=57,58,59,60 (landing room)
- door at x=61.

Also hoop 6 at (x=54, y=10) — mid-air collect between spikes? Between spike at 52 and pair at 55,56: bouncing to grab hoop at x=54, y=10 requires a bounce at around x=53... risky. Better: hoop 6 at (x=50, y=10) between spikes at 48 and 52 — the standard "bounce over the spike, grab hoop" — hmm also tight-ish. Since a full bounce peaks at 3 tiles, and the ball passes through hoop row 10 on the way up and down. Let's think about grab geometry: hoop center at (50.5, 10.5) tile-center coords. Ball radius 0.5 tile. Ball center at y=12.5 on ground; apex center y=9.5. So the ball's circle overlaps the hoop region (a ring around the tile center, radius ~0.35 of a tile with contact detection radius ~0.8) during much of the flight. If the hoop is at row 10, the ball overlaps it for y_center in ~[9.7, 11.3], which happens during most of the flight. So the timing needs horizontal alignment: you should be at x≈50.5 when the ball's center is between 9.7 and 11.3, on the way up or down. If the ball launched at x=48.7 (just after the spike at 48), traveling 6 t/s... at 0.2s it's at x=49.9 with center y=12.5-(11.49*0.2 - 11*0.04)= let's compute: y displacement up = v*t - 0.5*g*t² = 11.49*0.2 - 11*0.04 = 2.298-0.44=1.858 → center y = 10.64 ✓ overlapping. So at x≈49.9 → close to 50.5; collect. Fine — hoops with generous overlap detection make this forgiving. I'll make hoop collection radius generous (distance from ball center to hoop center < 0.9 tile).

To be safe I'll place hoops mostly in forgiving spots: some above ground level requiring just a bounce in place.

Let me finalize hoop placements:
1. (6, 12) — above ground, roll or hop.
2. (10, 10) — hop in place.
3. (19, 10) — hop in place after the walls.
4. (34, 10) — just past the pit, hop. Hmm, right after landing at 33, hop at x=34 collects. Fine.
5. (43, 10) — hop (before checkpoint 2? CP2 at 44). Fine.
6. (54, 10) — between spikes at 52 and 55: needs a hop while traversing. Let me instead put hoop 6 at (57, 11) — after the pair, low, and you grab it while landing... Or above the pair at (55.5)? Can't do half tiles.

Alternative for hoop 6: put it high over the pair of spikes but reachable: (56, 10). To grab it, the player bounces from x≈54 (before the pair) and clears the pair while collecting — that's the climactic last hoop. Risky? Jump from x≈53.8: at 6 t/s the ball clears x=55,56 within the flight; the hoop at (56.5, 10.5) needs center y in [9.7,11.3] at x=56.5 → t = (56.5-53.8)/v_x. With v_x=6: t=

Empty dir, node available. Good — I'll write the level data, verify with node, then write the rest.

Let me write index.html, style.css, game.js. Start with the level data inside game.js.

Let me carefully build the 64-char strings.

Ground row (13): 
- idx0: wall → '#'
- 1..29: '.' → 29 chars
- 30,31,32: 'o' (pit opening, no tile) → 'ooo'
- 33..62: '.' → 30 chars
- 63: '#' (wall)

Let me verify: 1 + 29 + 3 + 30 + 1 = 64 ✓

Row 14: same but without the hoops: '.' for 30..32.
Row 15: 
- 0: '#'
- 1..29: '#' (29)
- 30,31: '^'
- 32: '#'
- 33..62: '#' (30)
- 63: '#'
→ '#' + '#############################'(29) + '^^' + '#' + '#'(30) + '#' = 1+29+2+1+30+1 = 64 ✓

Wall at x=14 rows 11,12; wall at x=21 rows 11,12.

Row 12: 
- 0 '#'
- 1..13 '.' (13)
- 14 '#'
- 15..20 '.' (6)
- 21 '#'
- 22..36 '.' (15)
- 37 'S'
- 38..39 '.' (2)
- 40..42 '#' (ledge, 3)
- 43..62 '.' (20)
- 63 '#'
Total: 1+13+1+6+1+15+1+2+3+20+1 = 64 ✓

Row 11:
- 0 '#'
- 1..13 '.' (13)
- 14 '#'
- 15..20 '.' (6)
- 21 '#'
- 22..62 '.' (41)
- 63 '#'
Total: 1+13+1+6+1+41+1 = 64 ✓

Row 10:
- 0 '#'
- 1..63 '.' (63)
Total 64 ✓

Rows 0-9: '#' + 62 '.' + '#'.

Now with markers inserted:
- '@' at (x=3, y=12): row 12 index 3 → '.'→'@'
- 'c' at (26,12) and (44,12)
- 'o' at (6,12),(10,10),(19,10),(34,10),(45,12),(54,10)
- 'C' at (41,9)
- 'E' at (61,11),(61,12)

Note row 12 at x=34 is '.', x=45 '.', x=54 '.' — all '.' in row 12 (they're in the 43..62 range) ✓. x=41 in row 9 is '.' ✓.

Let me now write out the rows explicitly with careful character counts. I'll write them into the file and then verify with a node script that pads/reports lengths. Let me generate them programmatically first to avoid errors, then paste into game.js.

Actually smart: I'll write a small node generator script that builds the rows from rules and prints them, then I paste the output into game.js. Let me do that.

The map looks right. Let me double check a couple of visual things:
- x=45 hoop 'o' and x=44 checkpoint 'c' in row 12: at y=12, "co" at x=44,45 ✓. But wait, the crystal C at (41,9) sits above the ledge (40-42, y=12). The C is drawn at row 9, sitting on top of row 12? That leaves rows 10,11 empty between. The crystal rests on the ledge top (y=12 top edge) — but the marker is in row 9, not row 11. I placed it at y=9 (the row above the ledge would be row 11). Let me fix: crystal should be at (41,11) to visually sit on the ledge. But then the pickup is at the same height as the wall tops at x=14,21 — no matter.

Hmm, if the crystal is at (41,11), the ball landing on the ledge center (occupying row 11) overlaps it ✓ automatically. That's better: "crystal ball at (41,11)" resting on the ledge.

But wait, is (41,11) reachable? Yes as analyzed — land on the ledge.

Also consider: from below, can the player reach the ledge from the ground at x=43? Ground y=13 surface; rise 3 → apex bottom y=10, and the ledge top is y=12 — so from the ground the ball's bottom reaches y=10 at apex, which is ABOVE the ledge top (y=12)! So the player can jump straight onto the ledge from the ground below without the intermediate wall at x=37. Rise needed = 1 tile only... wait: ground surface top is y=13; ledge top is y=12; that's only 1 tile higher! I mis-designed: the ledge at rows 12 is only 1 tile above the ground rows 13. The "ledge" is 1 tile higher than the floor.

Hold on. Ground rows 13,14,15 solid → walking surface at y=13. A ledge made of solid row 12 → its top surface is y=12, i.e. only 1 tile above the floor. That's a step, not a high ledge! I earlier mistakenly thought the ledge top was at y=9.

So the crystal ledge needs to be higher: put the ledge at rows 9 (top y=9) → rise of 4 from the ground floor, requiring the intermediate step at (37, rows 11-12, top y=11, rise 2) then ledge rise 2 from y=11 to y=9. So: ledge solid at row 9 for x=40..42? But then it's floating in the air with nothing below it (rows 10,11 empty) — that's fine visually (floating block), and it's a "high ledge" as the spec suggests. Let me place the ledge at row 9 and the crystal at (41,8).

Hmm, but floating blocks may look odd; the spec says flat geometric — floating platforms are fine in this genre.

Alternatively: make the ledge thicker (rows 9,10,11 solid = a tower) but then you can't get on top... you can, by jumping from the step. A solid tower at x=40..42 from row 9 down to the ground would form a wall you can't climb except from the step. Let's do a floating slab: row 9 and row 10 solid (2 tiles thick) at x=40..42? Or just row 9 (1 tile thick slab). One tile thick slab at y=9 for x=39..43 — but the player jumping up from the step at (37, top y=11): rise needed to land on top of the slab = from y=11 to y=9 = 2 ✓. The slab's underside at y=10; standing on the step at x=37 (ball occupies row 10 at (37,10))! Conflict: the ball standing on the step top (y=11) occupies row 10, and the slab at x=39..43 row 10? No — if the slab is at row 9 only, its bottom edge is at y=10, and the ball on the step occupies rows [10,11] exactly → touching the slab bottom at y=10 → snag when moving right. So the slab must be at row 9 and further away horizontally: step at x=37, slab starting at x=40 leaves 2 empty columns (38,39); when the ball jumps from the step at x≈36.5 and rises, at x=39 its center must be above y=9.5-ish to avoid hitting the slab's left corner... Actually the ball rises; the danger is hitting the slab's underside (bottom face at y=10) or its left face. The ball's bottom must be above y=10 (clear the underside) before crossing x=40 - 0.5 = ... hmm let's think in terms of "ledge clearance":

Standing on the step (bottom at y=11), jumping gives bottom apex at y=11-3 = 8. The slab bottom is at y=10 (row 9 spans y=9..10). The ball's bottom passes y=10 at a rise of 1: t = 0.0916s. So after 0.09 s, the ball is above the slab's underside level and can move right freely. If the ball is at x center 36.5 at launch and moves at ≥1.1 t/s (needs to travel ≥ 3.0 to reach x=39.5 where the slab starts at x=39 with a ball radius...). At 6 t/s, in 0.09s it moves 0.55 tiles → x=37.05. It can then continue moving right while above y=10 as long as it's rising... The ball stays above the underside level (bottom above y=10, i.e. rise ≥1) for t ∈ [0.0916, 0.951]. During that time it travels up to 5.2 tiles at 6 t/s → from 37 to 42.2 — plenty to get onto the slab region and land on top (top y=9).

But: landing ON TOP of the slab requires the ball's bottom above y=9 before crossing x≥38.5 (slab left edge minus radius). The ball's bottom is above y=9 (rise ≥2) for t ∈ [0.22, 0.82]. To cross x=38.5, must travel ~2 tiles from 36.5 → at 6 t/s that's t=0.33 ∈ [0.22,0.82] ✓. At 3 t/s, t=0.67 ✓ also fine. So with speed 3–6 it works. At 1 t/s it won't reach (would need to be above y=9 at t=2s — impossible). So the player must approach with some speed. Reasonable, and the step gives a runway.

Hmm, but there's another snag risk: if the ball jumps while too close to the step edge... it's forgiving enough. Also there's a simpler alternative: the player can reach the slab from the ground below? Ground bottom at y=13, rise 3 → bottom apex y=10, which is below the slab top y=9. No — cannot reach from the floor. Good, so the step is required: a genuine detour.

So revise: slab at row 9, x=39..43? Careful: the slab's underside (y=10) is 2 tiles above the ground floor (y=12 = the row the ball occupies when rolling on the ground; ball center y=12.5, top y=12). Ball rolling on the ground occupies row 12 → clearance below the slab (bottom at y=10) is rows 10,11,12 = 3 tiles ✓ plenty.

Hmm wait, does the slab at row 9 x=39..43 conflict with hoop 5 at (45,10)? Adjacent but fine.

And can the slab block the critical path vision? No.

Now, the step at x=37: rows 11,12 solid (top y=11). But rolling right along the ground at 6 t/s, a player who doesn't jump hits a 2-tall wall — must have jumped. That's the pit-crossing landing zone though; the landing area is x=33..36. OK.

Wait, actually, hmm: the step at (37, rows 11-12) is 2 tall, and the walls earlier at x=14 and 21 are 2 tall too. Consistent.

Where's the crystal? On the slab at row 8: (41, 8). ✓ (rests on slab top y=9.)

Let me also reconsider: should I make the slab thicker for visual weight: rows 9 only is a 8px-thick slab, 5 tiles wide. Looks like a platform. Fine. Maybe make it x=39..43 (5 wide) so landing is forgiving.

Let me recheck crystal reachability with the slab from x=39: landing on top requires crossing x=38.5 (slab left edge 39 minus ball radius 0.5) while the bottom is above y=9 (rise ≥2 from step top y=11). As computed ✓ with speed 3+.

Actually, one more consideration: the ball can also land on the slab from above/right? Not relevant.

Escape from the slab: jump off or walk off the right edge (x=43) falling 4 tiles to the ground (rows 12 landing) ✓ safe.

Now let me also double check the earlier claim that the player cannot accidentally bonk the slab's underside while jumping over it on the critical path... The critical path is the ground under the slab; jumping in that area is only needed for the spike at 48, which is 5 tiles from the slab (x=39..43) — if the player jumps right at x≈47 they'd hit the slab? The slab spans x=39..43; at x=47 there's no slab. Jumping anywhere under the slab region (x 39..43) would bonk the underside — a 1-tile bonk (harmless), then land. Not near the spike at 48 (5 tiles away). OK.

Now let me regenerate with these fixes and then also write the game.

Also, I realize I should double check the geometry of wall jumps at x=14, 21 relative to the ceiling (none). Fine.

Updated map:
- slab: row 9, x=39..43 solid.
- crystal: (41,8).
- step: (37, rows 11,12).

Wait, one more check on the slab: from the step top (y=11) the player jumps; but the slab's left edge at x=39 is 2 tiles from the step's right edge at 38. If the player stands on the step at x=37.0 (center), rolls right off the step edge (x=38) and falls to the ground (2 tiles) — fine.

Let me regenerate.

Map is good. Now let me verify physics reachability numerically with a headless simulation harness. First I'll write game.js, then extract the physics for verification.

Let me write the files now. Start with index.html and style.css, then game.js.

game.js structure:
1. Level data + parse + validation
2. Constants
3. Input
4. Physics (step, collide)
5. Entities state (hoops, checkpoints, crystal, exit)
6. Death/respawn/gameover
7. Camera
8. Effects (squash, burst)
9. Render
10. HUD
11. Screens
12. Main loop with accumulator

Let me write it carefully.

```js
'use strict';
/* ---------- constants ---------- */
const TS = 8;                 // logical px per tile
const VIEW_TW = 16, VIEW_TH = 16;
const VW = VIEW_TW*TS, VH = VIEW_TH*TS;   // 128x128
const HUD_H = 16;
const DT = 1/120;             // fixed sim timestep
const GRAV = 22;
const FALL_MAX = 14;
const ACC = 18;
const VMAX = 6;
const FRICTION = 12;
const AIR_CTRL = 0.4;
const REST = 0.35;
const BOUNCE_H = 3.0;
const BOUNCE_V = Math.sqrt(2*GRAV*BOUNCE_H);
const R = 0.5;                // ball radius in tiles
const STEP_VY = 0.8;          // snap-down tolerance
const AXIAL_EPS = 0.02;       // overlap tolerance for walls
const SPIKE_D = 0.22, SPIKE_H = 0.18; // lethal inset
```

Level parse: map of chars; solid = '#'; spike = '^'; etc. Entities are extracted into arrays; the tile grid keeps only '#' as solid, and I'll keep a separate `spikeGrid` for rendering (and 'S' spike-on-top).

Tile chars:
- '#' solid
- '^' spike (lethal box inside tile, rendered inside tile)
- 'S' spike resting on top of the tile below (lethal box in the lower part of the tile)
- 'o' hoop, 'c' checkpoint, 'C' crystal, 'E' exit door (2 tall), '@' spawn, '.' empty

For rendering the solid, I want a subtle face highlight. Keep flat.

Collision: solid grid.

`isSolid(tx,ty)`: out of bounds → solid if ty<0? Let's make above-the-top non-solid (irrelevant). tx<0 or tx>=W → solid. ty<0 → non-solid (open sky, but our border walls prevent it). ty>=H → solid (shouldn't happen).

Simplify: out of bounds → solid. Then the border walls are redundant but harmless. Careful: if out of bounds is solid, and the ball is inside the level, no issue. But note the exit door tiles at x=61 aren't out of bounds.

Wait — the ball can never get to ty<0. Fine.

Move function:

```js
function moveAxis(b, d, axis){
  if(d===0) return false;
  if(axis===0){
    b.x += d;
    const minXi=Math.floor(b.x-R+1e-9), maxXi=Math.floor(b.x+R-1e-9);
    const minYi=Math.floor(b.y-R+1e-9), maxYi=Math.floor(b.y+R-1e-9);
    for(let xi=minXi; xi<=maxXi; xi++) for(let yi=minYi; yi<=maxYi; yi++) if(solid(xi,yi)){
      if(d>0) b.x = xi - R; else b.x = xi + 1 + R;
      b.vx = 0; hit=true;
      ...
    }
  }
}
```
Careful: when resolving, must break out and recompute? Standard approach: find the max penetration among overlapping tiles and resolve. Simpler: since the ball is 1 tile and moves ≤0.2 tiles per step, the first found resolution works, but resolving to xi-R with multiple columns overlapping: for d>0 the blocking tile is the rightmost overlapping column... Actually we should resolve against the nearest blocking face. Let me collect all overlapping solid tiles and compute the minimal correction. For d>0: newX = min over blocking tiles of (xi) - R. For d<0: newX = max over tiles of (xi+1) + R. Similarly for y.

That's robust. Implement:

```js
function solidBoxHits(b){ // returns list of overlapping tiles given current position
  const out=[];
  const minXi=Math.floor(b.x-R+EPS), maxXi=Math.floor(b.x+R-EPS);
  const minYi=Math.floor(b.y-R+EPS), maxYi=Math.floor(b.y+R-EPS);
  for(let yi=minYi;yi<=maxYi;yi++)for(let xi=minXi;xi<=maxXi;xi++) if(solid(xi,yi)) out.push([xi,yi]);
  return out;
}
```
Hmm, EPS with floor: if b.x-R is exactly an integer (ball touching the tile edge from the right), floor gives that column index; the ball touches but doesn't penetrate. With EPS=1e-9 the overlap depth is 0 → we should ignore zero-overlap. I'll instead compute overlaps with a strict condition: tile overlaps if (xi < b.x+R-EPS) && (xi+1 > b.x-R+EPS) ... i.e., overlap depth > 0 after epsilon.

Let me write horizontal resolution:

```js
function moveX(b, d){
  if(!d) return 0;
  b.x += d;
  let hit = 0;
  const y0 = Math.floor(b.y - R + EPS), y1 = Math.floor(b.y + R - EPS);
  for(let yi=y0; yi<=y1; yi++){
    if(d>0){
      for(let xi=Math.floor(b.x - R + EPS); xi<=Math.floor(b.x + R - EPS); xi++){
        if(solid(xi,yi)){
          const pen = (b.x + R) - xi;
          if(pen > EPS){ if(-pen < hit ... }
        }
      }
    }
  }
}
```
Getting convoluted. Simpler clean version:

```js
function collideX(b){
  const minXi = Math.floor(b.x - R + EPS), maxXi = Math.floor(b.x + R - EPS);
  const minYi = Math.floor(b.y - R + EPS), maxYi = Math.floor(b.y + R - EPS);
  for(let yi=minYi; yi<=maxYi; yi++){
    // pushing right out of tiles on the left, pushing left out of tiles on the right
    // determine by velocity sign
  }
}
```
Cleanest: after moving x, for every overlapping solid tile compute required push:
- If vx>0 (moving right): candidate x = xi - R (tile's left face). Take max over tiles? No — we need x ≤ xi - R for every blocking tile, so x = min over blocking tiles of (xi - R). But since a wall column block is contiguous, taking the min is correct and safe (never leaves penetration).
- If vx<0: x = max over blocking tiles of (xi+1+R).

Then set vx=0 and register a wall hit. Do the same for y: vy>0 (down): y = min(yi) - R; vy<0 (up): y = max(yi+1) + R.

But there's the subtlety: after moving x, the ball may overlap tiles it wasn't overlapping in y before. Because y hasn't moved and there was no penetration in the y pass, the vertical overlaps are fine. Standard and works.

For the y pass with landing: after moving y down, overlapping tiles → y = minYi - R, vy handled: if bounceHeld → vy = -BOUNCE_V else vy = -vy*REST (and if |vy| < settle → 0). Set grounded if vy>=0 collision.

Wall collision in x: vx = 0 (no bounce).

Corner snag: since x is resolved first and then y, the classic snag (pressing against a wall while falling, then being pushed back) doesn't happen because we resolve per axis independently and the ball is only pushed along the current axis.

Also for the ceiling (moving up into a solid): resolve and vy = 0 (or small downward?). Just 0.

Edge case: `hitWall` for x → vx = 0. Then next frame the ball can't move into it. Good.

Now, one important interaction: the pit shelf landing — the ball falling against the wall side at x=33 while in the pit: x pass pushes it back (vx=0), y pass lands it. Fine.

Now let's write the code for real. I'll write game.js in 2-3 chunks.

Rendering details:
- Background: fill VIEW with #141628. Then per visible tile draw:
  - solid: fill #2e3560; if tile below is not solid → top highlight: fill rect (x, y, 8, 1) #5b6bd6.
  - Also if the tile above is not solid, we already handle; if the tile to the left is not solid, draw a 1px vertical edge? Skip.
- Spike: color '#d94f6a'? Red conflicts with the ball (#ff3355). Use white-ish '#e8ecff' for spikes. Good contrast, distinct from the red ball, cyan hoops, yellow checkpoint.
- Ball red: '#ff2d3f' with a 1px dark outline '#7a0f22'. Add a white speck? Keep flat with an outline.

Ball marker for rotation: draw a small dark circle offset by rotation, or two dark "stripes". Simple: after drawing the red circle, draw a darker small circle at the center offset by (cos(rot)*r*0.45, sin(rot)*r*0.45) and its opposite. Use arc.

Squash: rx = R*sx, ry = R*sy where sy = 1 + squash, sx = 1/sy-ish. Let's track `sq` (squash amount 0..0.4 decaying) and `st` (stretch 0..0.35). sy = 1 + st - sq; sx = 1/sy (preserve area) → ellipse. Then clamp.

Effects decay with real dt (visual only). Use dtSim? Use the frame dt but clamp — visual only, acceptable. Actually to keep "simulation identical at different refresh rates", physics must be fixed; visuals can be frame-based but should ideally use the same accumulator. I'll decay effects using accumulated steps (count * DT) — same thing, deterministic. Simplest: decay inside the physics step using DT → deterministic. Do that (they're not physics-affecting).

Camera: camX in tiles, top-left. camX_target = ball.x - VIEW_TW/2 (center). Lerp factor per step: camX += (target-camX) * min(1, 12*DT). Clamp to [0, W-VIEW_TW]. Since level height == viewport height, camY = 0.
Also the camera should look ahead slightly based on direction? Keep centered per spec ("keeping the ball near the horizontal centre").

Rounding: drawOffsetTiles = Math.round(camX * TS)/TS? Let's compute px = (camX*TS); use `Math.round(px)` for the integer pixel shift, then tile drawing uses (tx - floor(px/TS))... Hmm. Approach: 
```
const camPx = Math.round(camX * TS);       // integer camera offset in logical px
const startTx = Math.floor(camPx / TS);    // first tile column
// draw tile at screenX = tx*TS - camPx  (integers)
```
Since camPx is an integer and TS=8, screenX is an integer ✓. Also entities at (x*TS - camPx) rounded.
Clamp camPx to [0, (W-VIEW_TW)*TS] as well.

Camera only scrolls horizontally ✓.

Spikes rendering: floor spike (^): base at the tile bottom: draw a saw with 3 teeth across the tile width, base at y=tile bottom, tips at y=tile top+2. For 'S' spike-on-top: base at y = tile bottom (which rests on the block below) and tips at tile top + 2 — same shape actually! Both are 1 tile cells; the visual difference: for a floor spike the base is on the tile's bottom edge; for an on-top spike the base is also on the tile's bottom edge (that's the top of the block below). So identical rendering. Fine — the hitbox differs.

Actually for the pit spikes, the tile below is bedrock? Pit spikes at (30,15),(31,15) — the tile below is out of bounds. Base at the tile bottom = y=16. Fine.

Burst effect: 8 fragments: each {x,y,vx,vy,life}. Update: pos += v*dt; life -= dt; render as 2x2 squares with alpha; lifetime 0.4s. Also a ring outline expanding: radius from 2 to 12 px over 0.4s.

Death flow: state 'dying' with timer 0.45s. On finish: lives--; if lives<=0 → state 'gameover' with timer ~1.6s → then title reset. Else respawn, state 'play'.

Score/HUD: build the HUD innerHTML only when values change (track last string). Lives icons: N spans (max 5). Hoops remaining: number. Score: 8-digit padded.

Screens: overlay div with class; content built via innerHTML. Title: h1 BOUNCE, p press space, p controls. Level complete: "LEVEL COMPLETE" + score lines + hint. Game over: "GAME OVER" + score + hint.

Overlay CSS: absolute over the screen area (top:0, height:128px*scale), flex center, background rgba dark (solid). Use classes for the text sizes in viewport units — simplest: draw the screens INSIDE the canvas as well! That guarantees crisp scaling and no HTML/CSS sync issues. Hmm, but HTML text is easier to style nicely. Actually drawing text on the canvas with scaled logical px: set `ctx.font = '8px monospace'` and use the integer scale... text drawn under a scale transform of 5x would be blurry-ish? With imageSmoothingEnabled=false, text is rendered by the font rasterizer at the transform's resolution — Canvas applies the transform to the font too (font size 8px * scale 5 = 40 device px), so text renders crisply at the device resolution. Yes: canvas transforms apply to text rendering (the glyph rasterization happens at the transformed size), so text is sharp. Good — but "monospace" at 8px logical → effectively 40px, sharp.

I'll do screens in the canvas with `ctx.font = '7px monospace'` etc. That guarantees perfect alignment with the 128×128 viewport. Simpler and self-contained. But then HTML/CSS is just the page shell + HUD. Fine.

Hmm, but the spec says the HUD bar is HTML? It doesn't specify — "Keep a single HUD bar fixed below the 128×128 world viewport". Canvas-drawn HUD inside a separate area also satisfies it (a bar fixed below the world viewport inside the canvas). I'll do the HUD in the canvas too — inside the canvas's HUD region (y from 128 to 144 logical px). Then everything is pixel-consistent, and CSS handles the page + frame + crisp scaling. But: "one small ball icon per remaining life" — easy to draw circles in canvas ✓.

Decision: everything in the canvas (world + HUD bar + screens), CSS only for the page frame. The canvas backing store is 128×144 logical * scale = 640×720 device px, with CSS width 640px etc. Set ctx.scale(S,S) once (in resetTransform after resize).

Then the HUD is at logical y=128..144 ✓ below the world viewport, and never hides a map row (world rows occupy y<128) ✓.

Font: use `'6px monospace'`? For the 8-digit score: at scale 5, 6px logical → 30 device px tall — quite big for the HUD bar of 16 logical px. Let's use a font of 7 logical px for the score (fits a 16px bar), 6px for small labels, and ~16px for the title. Use monospace with letterSpacing? Canvas letterSpacing is supported in modern browsers but let's not depend on it.

Actually, drawing the score with a fixed-width digit layout: measureText on monospace gives consistent widths. 8 digits at 7px monospace ≈ 8*4.2=33.6 px. Fine, right-aligned at x=126.

Hmm, using fractional measureText results may cause jitter — compute once and cache.

Let's write the code now. I'll be pragmatic and clear.

Also handle: keydown for Space on title/complete/gameover; ensure the space keyup doesn't interfere. Use a `justPressed` guard? If the ball is dying and the player holds space... The transition happens automatically; a held Space would immediately skip. Add a small lockout timer (~0.6s) on entering title/complete/gameover before accepting input, and require a *fresh* keydown (track key state transitions: handle in keydown event only, and when entering a screen set `inputLock = 0.5s`; ignore keydowns while locked... but a keydown held from before doesn't re-fire? Auto-repeat DOES fire keydown repeatedly. So the lockout must be time-based; I'll also clear on keyup. Use both: lock timer 0.5s during which keydown is ignored for transitions.

Now the main loop:

```js
let acc = 0, last = 0;
function frame(now){
  const t = now/1000;
  let dt = t - last; last = t;
  if(dt > 0.25) dt = 0.25;
  acc += dt;
  while(acc >= DT){ simStep(DT); acc -= DT; }
  render();
  requestAnimationFrame(frame);
}
```

simStep handles screen timers too (so transitions are frame-rate independent).

Also the HUD text/visual is drawn from state each frame ✓.

Let me now also think about `preventDefault`: on keydown, if the key is in our set → e.preventDefault().

Let me write it. Also validation: check counts, check spawn not in solid, log warnings via console.assert and also display? Just console.

Let me write the file.

For determinism check later, I'll add a hidden global `window.__BOUNCE__ = {sim, state...}` for a headless test harness? A nice touch for verification: expose an API for testing. I'll expose `window.BOUNCE_TEST = { state, input, step, ... }` — harmless and lets me run a node-based check... but node can't run canvas. I'll instead extract the physics into a testable form by writing a standalone node script that copies the physics functions? Better: structure game.js so that physics functions are defined in a way that a node harness can load it with a stub DOM. I'll add a guard at the top: if (typeof document === 'undefined') → run headless mode? Simpler: in the node test harness, I'll read game.js, strip the browser section, and eval the physics part. To make that easy, I'll put the physics in a clearly delimited block and expose it via a factory function `Physics` that doesn't touch the DOM.

Cleanest approach: write game.js such that it defines `const B = { ... }` (a module object with pure sim functions + state) and then does DOM setup only if `typeof document !== 'undefined'`. In node, I can `const src = fs.readFileSync('game.js'); eval(src)` and access B via a var? eval with const in the same scope... I can use `new Function(src + '; return B;')()`. That works if game.js defines B at the top level of the function scope. Let me structure game.js as:

```js
const B = (() => {
  // pure data + physics, no DOM
  return {...};
})();
// DOM layer guarded by typeof document/document !== undefined
```
Then the node harness: `const B = new Function(src + ';return B;')();`

But the DOM layer would throw in node — guard it: `if (typeof document !== 'undefined') { ... }` — a block statement containing `const canvas = ...`. Function declarations inside blocks are fine (let/const scoped). Hmm, the render function declarations would need to be inside the guard too, and the main loop. That's fine, since all rendering happens in the guarded section. But `B` needs to hold the game state and the step function which the guarded section drives. That's a slightly awkward architecture, but it makes the sim verifiable headlessly — which the task explicitly asks me to check ("play it through in your head", "verify object counts", "behaves the same at different frame rates"). I'll do it: a "sim module" and a "browser shell".

Structure:
```js
const B = (function(){
  'use strict';
  const LEVEL = [...];
  const CFG = {...};
  // parse
  // state object
  // reset(), input {left,right,bounce}
  // step(dt) -> advances sim by fixed dt
  // returns {CFG, state, step, resetToTitle, startRun, ...}
})();
if (typeof document !== 'undefined') { /* DOM shell + loop + render */ }
```
The state machine inside B: 'title' | 'play' | 'dying' | 'complete' | 'gameover'.

Good. Let me write.

Careful with the level data being long strings — fine.

I'll write game.js in 2 chunks: chunk 1 = sim, chunk 2 = browser shell.

Let me write out the code.

```js
/* ==================================================================
   BOUNCE - Level 1
   sim module (no DOM) + browser shell (canvas render + input)
   ================================================================== */

const B = (function () {
  'use strict';

  /* ---------------- level data (parsed at load) ---------------- */
  const LEVEL = [
    '...16 rows...'
  ];

  const TS = 8;             // logical pixels per tile
  const VIEW_TW = 16, VIEW_TH = 16;
  const VIEW_W = VIEW_TW * TS;   // 128
  const VIEW_H = VIEW_TH * TS;   // 128
  const HUD_H = 16;
  const DT = 1 / 120;
  const CFG = {
    gravity: 22, fallMax: 14, accel: 18, maxSpeed: 6, friction: 12,
    airControl: 0.4, restitution: 0.35, bounceHeight: 3,
    radius: 0.5, settleVy: 0.8, snapDown: 0.8, eps: 1e-7,
    spikeInsetX: 0.22, spikeInsetTop: 0.20, spikeInsetBottom: 0.0,
    hoopGrab: 0.95, checkpointGrab: 1.05,
    deathTime: 0.45, gameOverTime: 1.8,
    maxLives: 5, startLives: 3,
    scoreHoop: 100, scoreCheckpoint: 200, scoreCrystal: 1000,
    scoreLevel: 500, scoreLife: 1000
  };
  CFG.bounceV = Math.sqrt(2 * CFG.gravity * CFG.bounceHeight);
```

For spikes: floor spike hitbox: x in [tx+0.22, tx+0.78], y in [ty+0.20, ty+1]. For 'S': same x inset, y in [ty+0.20, ty+0.78]? Let's say the on-top spike's lethal region is y in [ty + 0.25, ty + 0.80] and the visual base at ty+0.75 (so the visual sits on the block top at ty+1? hmm).

Wait. For an on-top spike at (37,10) sitting on the pillar whose top is at y=11 (tile 11 top edge = 11.0). The tile 10 spans [10,11]. The base of the spike visual should be at the bottom of tile 10 = 11.0 = the pillar top ✓. So the visual spans y ∈ [10+spikeHeight, 11] where spikeHeight ≈ 0.75. Then the lethal region: y ∈ [10+0.25, 10+0.78] → the lethal box sits just above the pillar's top face at y=11.

For a floor spike (on the ground): base at the tile's bottom edge (ty+1), same visual: tips at ty+0.25. Lethal y ∈ [ty+0.25, ty+0.78] too — same rule for both! Simpler: one spike rule, box = [tx+0.22, tx+0.78] × [ty+0.25, ty+0.80]. Then a floor spike on the ground: ball resting on the ground has its bottom at ty+1 (the ground top). The spike box bottom at ty+0.80 → 0.2 clearance ✓.

For the pit spikes at (30,15),(31,15): base at y=16 (bottom of the map) ✓ same rule.

Great, uniform. And 'S' (spike on top of a block) vs '^' (spike on floor) — both render identically with the base at the tile bottom edge. So actually the map only needs one spike char! But I need to know the difference for rendering correctness: at (37,10), the tile below (37,11) is solid, so the base at the tile bottom edge looks correct. For '^' at (48,12), the tile below (48,13) is solid → base correct. For the pit (30,15), the tile below is out of bounds — the base sits at the map bottom ✓ correct. So a single spike char works for all cases! Nice simplification: all spikes are '^', and rendering puts the base at the tile bottom edge.

But careful about the hitbox for the pit spike: the ball falling into the pit from the shelf at x=32... The shelf: (32,13) and (32,14) are open; the solid at (32,15). So the pit interior is 2 tiles deep (rows 13,14) across x=30..32, with the floor solid at x=32 only and spikes covering x=30,31 whose lethal boxes span y ∈ [15.25, 15.8].

Hmm wait: the spike tile at (30,15) occupies the full tile visually but the lethal box is y∈[15.25,15.80], x∈[30.22,30.78]. If the ball falls into the pit at x=29.5 and lands on (30,15)... the ball's bottom hits y=16 (the tile (30,15) is solid!) — WAIT. Is the spike tile solid? I said spikes are non-solid. So the ball falls to y=16 (map bottom = out of bounds → solid). Hmm, out-of-bounds-below: if isSolid(y>=H) returns true, the ball rests at y = 16 - 0.5 = 15.5 → its center is inside the lethal box y∈[15.25,15.8] at x∈[30.22,30.78] → dies. And on the shelf at x=32 the ball rests at 15.5 with x∈[31.5,32.5] → outside the lethal x-range ✓ survives.

Good, consistent. But relying on out-of-bounds solid for the pit floor is subtle. Better: make row 15 solid everywhere (bedrock) and put the spike tiles ABOVE it? Then the pit spikes would be at row... hmm, the pit floor is row 15. If row 15 is solid and the spike is at (30,14)... no.

Alternative: keep spikes non-solid and make row 16 (virtual) solid via out-of-bounds = solid. That's fine and I'll explicitly document it. Actually, cleaner: in the map, make the pit floor explicit: keep row 15 solid ('#') everywhere including under the pit, and put the pit spikes at row 14 as 'S' spikes sitting on the bedrock! Let's reconsider:

Pit: rows 13,14 open at x=30,31,32 with the floor at row 15 = '#' (bedrock). Spikes at (30,14) and (31,14) as 'S' → their tile spans [14,15], base at the bottom edge 15 = bedrock top ✓, lethal y ∈ [14.25,14.80]. A ball resting at the pit bottom (on bedrock at y=15) has center 15.5; if x ∈ [30.22,30.78] → dead ✓. Shelf at x=32 (no spike) → safe ✓.

But wait, with row 15 solid under the pit, and the surrounding ground being rows 13,14,15, the pit is 2 tiles deep ✓ same as before.

But hold on: the spike tile at (30,14) — the ball jumping across the gap at a height where its bottom is at y≈13... does it overlap the spike's lethal box y∈[14.25,14.80]? Only if the ball descends into it. ✓ Fine.

Now row 13 and 14 strings: pit = '...' at x=30..32 for both rows, row 15 = all '#' except the 'S' markers at 30,31? But 'S' is in row 14, so row 14 at x=30,31 = 'S' and row 13 = '.'.

Let me redo:
- Row 13: x 1..29 '.', x 30..32 '.', x 33..62 '.' → i.e., row 13 is all '.' except borders. Wait no! Row 13 IS solid ground in the non-pit areas: rows 13,14,15 are solid ground. So row 13 = '#' except at x=30,31,32 (the pit opening) = '.'.
- Row 14 = '#' except x=30,31 = 'S' (spikes) and x=32 = '.' (open above the pit floor at x=32).
- Row 15 = '#' everywhere.

Hmm, careful: the spike tile at (30,14) — the spike's own tile is inside the pit opening. Visually the pit interior at x=30 shows: row 13 = empty (dark), row 14 = spike (base at y=15), and the ball must not overlap y∈[14.25,14.8] ✓.

Now the map is cleaner: no reliance on out-of-bounds solids for the floor (though I'll keep OOB solid as a safety net).

Let me regenerate the map with this change. Also double-check the pit depth: the ball standing on the bedrock at the pit bottom: bottom y=15; surrounding ground surface at y=13 → 2 tiles lower ✓. Escape: bounce rise 3 → bottom reaches 12 → clears the ground top (13) with 1 tile margin ✓. Escape requires moving horizontally while above y=13: from x=32 (shelf) moving left is blocked by... nothing until x=29's right face at x=30? Wait the ground at x≤29 occupies rows 13,14,15 → its right face is at x=30 (the face between column 29 and 30). So the pit's left wall face is x=30, i.e. the ball can't move left past x=30.5. It must land on the ground to the left → top surface at y=13. From the pit floor at x≈31.5, jumping (bottom 15→12), moving left: it must cross x=30.5 with its bottom above 13 → the rise needed is 2 tiles at the moment x=30.5 → time window [0.220, 0.824] ✓ if moving left slowly. At 6 t/s, from x=31.5 it reaches x=30.5 in 0.167 s (rise 1.67, bottom 13.33 → still below the ledge top... at 0.22s, x=30.18 and rise 2.0 — it needs to be above y=13 (bottom) at x=30.5, i.e. at t=0.167 if starting at 31.5. Hmm: moving left, the ball's left edge crosses the wall face x=30 when its center = 30.5. The wall (col 29 rows 13,14) blocks the ball if the ball's bottom is below 13. So at t=0.167 (center x=30.5), the bottom must be ≤13 → but it's at 13.33 → blocked → the ball hits the wall face and slides down. But it keeps bouncing/horizontal pressure: the player holds left; each bounce repeats. Actually the ball can hop up in the air: it rises while sliding against the wall; once its bottom clears y=13 (t≥0.22) while still pressed against the wall, it continues moving left and lands ON the ground at x≈30 → wait, if the ball is at center x=30.5 and its bottom rises above y=13, then the region above is free (row 12 at x=30 is empty ✓), so the ball can move left onto the ground top and land at x≈29.5 ✓. It just takes a moment. So escape is automatic if you keep holding the direction and bounce. ✓ Not frame-perfect (there's a 0.6s window above the ledge level).

Also, from the pit floor at x=31.5 to the right (shelf x=32): the ball can rest there. From x=32 floor, escape right: same ✓.

OK. And what

The map is correct: 16 rows × 64 cols, 6 hoops, 2 checkpoints, 1 crystal, 2 exit tiles, 7 spike tiles (2 in pit + 1 on the stepping stone + 4 on the ground).

Now let me write index.html, style.css, then game.js (sim module first, then the browser shell).

Let me write game.js in two chunks: first the sim (with the map), then append the browser shell via edit.

Writing the sim carefully.

```js
const B = (function () {
  'use strict';

  /* ============ LEVEL DATA (parsed at load) ============ */
  const LEVEL = [ ...16 strings... ];

  const CHAR = { SOLID: '#', SPIKE: 'S', HOOP: 'o', CHECKPOINT: 'c', CRYSTAL: 'C', EXIT: 'E', SPAWN: '@' };

  const TS = 8, VIEW_TW = 16, VIEW_TH = 16;
  const VIEW_W = TS*VIEW_TW, VIEW_H = TS*VIEW_TH, HUD_H = 16;
  const DT = 1/120;

  const CFG = {...};

  // parse
  const level = parse(LEVEL);

  function parse(rows){
    const H = rows.length, W = rows[0].length;
    const solid = new Uint8Array(W*H);
    const tile = [];  // raw char grid for rendering
    const hoops = [], checkpoints = [], spikes=[], exitTiles=[];
    let spawn = null, crystal = null, exit = null;
    ...
  }
```

Exit door: two tiles; the door occupies a rect. The lower tile's bottom = ground surface. door = {x: minTx, y: minTy, w:1, h:2}. Solid when closed. Touching when open → complete: check the ball's box overlapping the door rect.

Ball state: {x,y,vx,vy, grounded, dead, rot, squash, stretch, deathTimer}.

Run state: {screen, lives, score, hoopsLeft, hoops[], checkpoints active index, crystalCollected, respawn:{x,y}, camX, timer, effects[], finalScore, deathCount? }

API:
- startRun(): reset everything, screen='play'
- toTitle(): screen='title'
- setInput(name, down)
- step(): advance one fixed DT (handles screen timers + physics)
- expose state for render/tests.

Score computation on completion: score += 500; score += 1000*lives; finalScore = score; screen='complete'.

Death: lives-- after the burst.

Also "3 deaths must produce Game Over": lives 3 → die 1 → 2 lives, respawn; die 2 → 1; die 3 → 0 → Game Over ✓.

Lives: max 5, start 3; the crystal gives +1 if lives<5. Note: "awards one life up to the maximum of 5" — if lives is currently 3 → 4 ✓.

Respawn point: latest active checkpoint position, else spawn. Store respawn as the exact position + zero velocity. Checkpoint respawn position: the checkpoint tile center at (cx+0.5, cy+0.5)? The ball should rest on the ground: at (26.5, 12.5) with the ground top at 13 → resting exactly ✓ (bottom = 13.0).

Respawn safety: ensure the respawn tile isn't solid/hazard — validated at parse.

Also: after respawn, brief invulnerability? Not needed (spikes are only where you'd have to walk in).

Effects: burst {x,y,vx,vy,life} in tile units, plus a ring.

Camera: camX target = clamp(ball.x - VIEW_TW/2, 0, W-VIEW_TW). Smooth: camX += (target - camX)*(1 - exp(-9*dt))... For determinism use a simple lerp factor: `camX = camX + (t - camX) * Math.min(1, dt*10)`. Deterministic given fixed DT ✓.

Also on death/respawn keep the camera (no snap) — or snap on respawn to avoid weirdness. Keep smooth (nice effect).

Ball rot: rot += vx * dt / R (radians per distance = distance/R for rolling without slipping: ω = v/R → rot += vx*dt/R).

Squash/stretch:
- On landing impact: squash = clamp(|vy|/BOUNCE_V * 0.35, 0, 0.35); if bounceHeld and landing → stretch = 0.3 instead (stretching up as it launches). Let's do: on landing set squash=impulse-based; on launch set stretch.
- In air: stretch proportional to |vy|: airStretch = min(0.18, |vy|/BOUNCE_V*0.18).
- Decay: squash -= dt*4 (0.25s decay).
- sy = 1 - squash + stretch, sx = 1/sy? For area preservation, sx = 1/sy. Clamp sy ∈ [0.6, 1.4].
Hmm careful: "Effects must not alter collision geometry" — drawing only ✓.

Hazard check: after moving, check spike overlap → die.

Order in step:
1. if screen != 'play' handle timers (dying timer) and return.
2. input → accel/friction/gravity/velocity.
3. move x, move y, resolve.
4. pickup/hazard/exit checks.
5. effects decay, camera.

Death handling sets screen='dying', ball.dead=true, spawn burst; after CFG.deathTime: lives--; if 0 → screen='gameover' (timer=gameOverTime) else respawn & screen='play'.

Game Over timer → toTitle() (fresh).

Level complete: screen='complete'; the run is over; the player presses Space → title? Spec: flow is Title → Level 1 → Level Complete (terminal). So on Level Complete, Space → title (fresh). I'll show "Press Space" on the complete screen → title. Same for Game Over (auto-return to title after a delay, per spec "show Game Over briefly, then return to the title screen").

Now render (browser shell):
- resize: compute scale = clamp(floor(min(innerW/VIEW_W, (innerH)/(VIEW_H+HUD_H))), 2, ...). Use max integer scale fitting: Math.max(1, Math.min(Math.floor(availW/ (VIEW_W)), Math.floor(availH/(VIEW_H+HUD_H)))). Use min(window.innerWidth-32, ...) etc.
- canvas.width = VIEW_W*S; canvas.height=(VIEW_H+HUD_H)*S; ctx.setTransform(S,0,0,S,0,0); ctx.imageSmoothingEnabled=false.
- Draw world translated by -camPx.
- Then HUD bar (drawn in logical coords, y from 128 to 144).
- Then screens over the world area (fill the whole canvas incl. HUD? The spec says screens; I'll cover the world viewport only and keep the HUD visible... simpler: cover the world area only, and dim the HUD too? For a title screen, cover the world region 0..128 and leave the HUD showing 3 lives etc. Hmm, on the title screen the HUD showing lives=3 and score 00000000 is fine/nice.

Title screen: I'll draw over the world area with the background color (opaque) + text.

Text drawing helper: `txt(str, x, y, size, color, align)`.

Let's pick the palette:
- BG '#141627'
- HUD bg '#1b1f36', top border line '#3a4270'
- SOLID fill '#2f3564', top edge '#5f6ecf' (1px), left/right edges slightly lighter? Let's add: bottom/right darker line '#232848'.
- SPIKE '#e6eaf8' with a 1px darker outline '#8e97c8'? Keep flat white-ish.
- HOOP '#22e0d0'
- CHECKPOINT inactive '#6b74a8', active '#ffd93d'
- CRYSTAL '#c58cff' with a white core
- EXIT closed '#94582f' bars '#5c3418'; open '#0f1020' with a cyan frame? Let's do: closed = '#8a4f2a' with vertical plank lines and a red lock dot? Simple: closed door brown with two diagonal-ish stripes. Keep it: frame color for the open door '#4dffb8'.

Ball '#ff2b45' with outline '#6e0b1c'.

Let me write the render code:

```
function render(){
  const st = B.state;
  ctx.setTransform(S,0,0,S,0,0);
  ctx.fillStyle = PAL.bg; ctx.fillRect(0,0,VIEW_W, VIEW_H+HUD_H);
  const camPx = Math.round(st.camX*TS);
  ctx.save();
  ctx.beginPath(); ctx.rect(0,0,VIEW_W,VIEW_H); ctx.clip();
  ctx.translate(-camPx, 0);
  // visible range
  const t0 = Math.floor(camPx/TS)-1, t1 = Math.floor(camPx/TS)+VIEW_TW+1;
  ... tiles ...
  ... entities ...
  ... ball ...
  ... effects ...
  ctx.restore();
  drawHUD();
  if(screen!=='play') drawScreen();
}
```
Note: the camera clip is the world area ✓ and out-of-bounds never shows because camX is clamped to [0, W-16] ✓.

Careful about drawing at fractional logical positions for entities: round to integer device px? Entities at (x*TS - camPx) may be fractional (e.g. ball center). Rounding to the nearest logical px keeps things crisp and avoids sub-pixel shimmer; the ball would then move in 1-logical-px steps (8 device px at scale 8!) — that's jerky. Better: no rounding for the ball (smooth sub-logical motion), rounding only for tiles. Canvas draws with antialiasing at fractional positions — that's fine (slight AA on the ball edge, which is actually good for a circle). For rectangles (hoop tiles etc.), fractional positions cause AA shimmer — but hoops/crystals are static in world space while the camera moves by fractional amounts... The camera offset is applied via translate(-camPx,0) where camPx is a rounded integer → tile art stays crisp ✓. Entities: use their fractional logical position relative to the rounded camera → static hoops would shimmer by sub-pixel amounts. To avoid, round entity positions to 1/... hmm, shimmer on a 8px ring moving sub-pixel is negligible and only happens while the camera moves. But "camera must not visibly jitter" refers to the world. I'll round entity positions to the nearest half logical pixel? Let me just round entities to integer logical px offsets from the rounded camera, except the ball (smooth). Static objects then stay perfectly crisp and static ✓, and the ball moves smoothly ✓. The ball is drawn as a circle (AA anyway).

Death burst fragments: 2x2 squares, positions rounded ✓.

OK, writing the code now. Also expose for tests: `B.state`, `B.input`, `B.step`, `B.startRun`, `B.toTitle`, `B.CFG`, `B.level`, `B.MATH` helpers.

Let me write chunk 1 (the sim).

One more detail: `input` object with left/right/bounce booleans. In headless tests I can set them directly.

Also: numpad keys. `e.code === 'Numpad4'` etc. And 'Space' / 'KeyW' / 'ArrowUp'.

Now writing.

For the fixed step, in `step()` I use CFG values with dt=DT.

Let me write:

```js
function stepPhysics(dt){
  const b = run.ball;
  const inp = input;
  const dir = (inp.right?1:0) - (inp.left?1:0);
  if(b.grounded){
    if(dir>0){ b.vx += CFG.accel*dt; }
    else if(dir<0){ b.vx -= CFG.accel*dt; }
    else {
      const f = CFG.friction*dt;
      if(b.vx > f) b.vx -= f; else if(b.vx < -f) b.vx += f; else b.vx = 0;
    }
  } else {
    if(dir>0) b.vx += CFG.accel*CFG.airControl*dt;
    else if(dir<0) b.vx -= CFG.accel*CFG.airControl*dt;
  }
  if(b.vx > CFG.maxSpeed) b.vx = CFG.maxSpeed;
  if(b.vx < -CFG.maxSpeed) b.vx = -CFG.maxSpeed;
  b.vy += CFG.gravity*dt;
  if(b.vy > CFG.fallMax) b.vy = CFG.fallMax;
  b.grounded = false;
  // horizontal
  moveX(b, b.vx*dt);
  // vertical
  moveY(b, b.vy*dt);
  // step-down (coyote-free): stay glued to ledges when rolling
  if(!b.grounded && b.vx !== 0 && b.vy >= 0){
    const wasY = b.y;
    moveY(b, CFG.snapDown);   // probe downward
    // keep the ball on the ground
    if(b.grounded){
      // landed via snap; treat as grounded but vy should be reset
      b.vy = 0;
    } else {
      b.y = wasY;
    }
  }
  ...
}
```
Hmm: moveY(b, snap) with a downward displacement: if it collides, the ball is placed on the surface and the landing handler runs (bounce!). That's wrong for a snap — a snap shouldn't trigger a bounce launch. Let me implement moveY with a flag: `moveY(b, d, isProbe)`, where the landing response (bounce/restitution) is only applied when !isProbe; and for a probe, set grounded=true, vy=0, no bounce.

But then when the player holds bounce while rolling on flat ground: the ball is grounded from the real collision (not the probe) each step, and bounceHeld → launches. Good. But what if the ball is grounded via a snap probe on one step, and then the real moveY in the next step: vy = 0 + g*dt → moves down 0.0015 tiles → collides → landing → bounce launches ✓. So the bounce still works on snapped ground the following step. 

Wait, careful: at the moment of snap, grounded=true. Next step: vy = g*dt ≈ 0.183 t/s → moveY(0.0015) → the ball is exactly resting on the surface, moving down 0.0015 → overlap → resolve → landing with |vy|=0.183 → if bounce held, launch at full BOUNCE_V (the spec: "if bounce is held at the moment of landing, the ball is launched to its full bounce height") ✓.

So the sequence: each ground contact launches. That gives a continuous bounce chain at full height while bounce is held ✓.

But: is that "landing without bounce held makes it settle quickly"? With bounce not held, on the first landing vy=-11.49 → +4.02 → apex 0.367 → land again with 4.02 → 1.41 → apex 0.045 → 0.49 → 0.17 → settle. Total ~0.6s of small hops. Each subsequent landing at 4.02: if the player presses bounce during that time, they get full height ✓. Hmm, that means pressing bounce within ~0.5s after landing still gives full height — that's forgiving and consistent with "every bounce is the same height". But it makes holding bounce continuously produce full-height hops ✓ intended.

Alternatively use a "bounce held at the moment of first contact only" rule. I'll keep it simple: any landing with bounce held → full launch.

Settle threshold: if |vy_after| < CFG.settleVy (0.8) → vy = 0, grounded = true. That ends the chain after ~0.2s.

Hmm, one subtlety: with restitution 0.35 and a bounce-chain at full height, the ball lands at -11.49 and launches at -11.49 (full). Energy conserved ✓ (deterministic, no drift because launch speed is a constant derived from height, not restitution).

Now, "the ball's apex should be exactly 3 tiles above the launch point" ✓ since launch speed = sqrt(2*g*h) and the launch position is at the resting position.

Terminal velocity 14 > 11.49 so it can only be reached after a longer fall (e.g., falling off the ledge: from ledge top y=9 to the ground y=13 is 4 tiles → v = sqrt(2*22*4) = 13.3 < 14 ✓ never capped in this level, except... nothing falls from higher than 4 tiles. Fine.)

Death check: check the ball's box vs spike lethal boxes AFTER collision resolution.

Pickups: after resolution, check hoops/crystal/checkpoints/exit.

Now write the collide functions:

```js
function solidAt(tx, ty){
  if(tx < 0 || tx >= W || ty < 0 || ty >= H) return 1;
  return level.solid[ty*W+tx];
}
```
Door closed → solid: set level.solid for door tiles dynamically (level is per-load static; the door state toggles). Use a mutable grid: `solidGrid` in the run state? The level grid is immutable geometry; I'll keep a separate `dynamic` grid where the door tiles are set to 1 when closed. Cleaner: `isSolid()` checks the static grid OR (door closed && tile in doorRect).

Let me implement `isSolid(tx,ty)`:
```js
if(tx<0||tx>=W||ty<0||ty>=H) return true;
if(staticSolid[ty*W+tx]) return true;
if(run.exitOpen === false && inDoor(tx,ty)) return true;
return false;
```
inDoor: tx === door.x && ty >= door.y && ty < door.y + door.h.

Good. Now let me write everything. I'll write chunk 1 and then append.

For validation logging: a `validate()` function returning an object; call it at load and console.warn if something's off. Also verify the ball spawn isn't solid/spiky.

Let me write the code.

Also for the headless test I want a function to place the ball and run: expose `B.sim = {ball, run, ...}`. I'll expose `state` (the run object) with direct mutation access ✓.

Now write.

HUD: lives icons: for i in 0..lives-1 draw a red ball circle r=3 at x=6+i*11, y=136. Hoops remaining: "HOOPS 3" in cyan at x=72? Then the score right-aligned at x=122. Let's see: 5 lives * 11 = 55 px wide → hoops label from x=62, score right at 122. Text 7px monospace: "HOOPS 0" ~ 7*4.2 = 29px → 62..91; score 8 digits at 7px ≈ 34 → 88..122. Overlap. Use font 6px: digits ≈ 3.6px → 8 digits = 29 → x from 93..122. Hoops label at x=60: "H 3" small. Let me measure at runtime with measureText and lay out dynamically:
- lives icons left.
- score right-aligned at VIEW_W-4.
- hoops text at VIEW_W-4-scoreWidth-14, left aligned... simpler: draw hoops centered at VIEW_W/2. With the score ~29px wide ending at 122, hoops centered at 62 is fine.

I'll draw: `HOOPS n` — spec says "the number of hoops remaining" — I'll include a tiny hoop glyph + the number to avoid ambiguity. Let me draw a small ring icon then the number. Good: at x=... let me compute: livesWidth = lives*11; then at x = 62 draw a hoop ring (6px) and text of the remaining count. Fine.

Let me write now — enough planning.

Also, the page: index.html with <canvas id="game"></canvas>, wrapped in a div with a border. Also a <noscript>? Not needed. Also prevent page scroll: `html,body{overflow:hidden}`.

Let me write the files.

Now style.css.

Note: the canvas has tabindex=0 so it can receive focus ("while the game has focus"). But keyboard events are better attached to window for robustness. I'll attach to window but preventDefault for game keys, so the page doesn't scroll. Also make the canvas focusable with an outline style.

Now game.js — part 1: the sim module. I'll write it, then append part 2 (the browser shell) with a separate write? No — write overwrites. I'll write part 1 with `write`, then append part 2 by using `edit` with the last line as an anchor. Let me plan: end part 1 with a marker comment line that I then replace.

Actually the guideline: "If a file is getting long, write it in chunks (write the first part, then append with edit)". So: write part 1 ending with `/* __APPEND__ */`, then edit to replace that marker with part 2.

Let me write part 1 (sim) now — it'll be maybe 300 lines.

Before writing the shell, let me verify the sim headlessly with node. But there's a bug I noticed: in stepPhysics the snap condition `if (!b.grounded && !wasGrounded === false && ...)` — that's wrong; `!wasGrounded === false` means `wasGrounded === true`... Actually `!wasGrounded === false` evaluates as `(!wasGrounded) === false` → `wasGrounded === true`. So the condition is: not grounded now, was grounded before, falling, moving horizontally → snap. That's what I intended (only snap when we just left a surface). But it should also snap when rolling off a small step from a non-grounded state? Let's think: the ball rolls along the ground, the ground ends (a real drop) — one step later it's not grounded (was grounded) → probe down 0.7 → if a solid is found within 0.7 tiles it snaps. For a 1-tile step-down this fires only if the step is within 0.7 tiles below. A ledge 1 tile lower: the ball leaves the ledge; the probe checks 0.7 tiles down and finds nothing (the drop is 1.0 tiles) → no snap → the ball falls. Hmm, that means it flaps ~0.07s before landing on the lower step, which could cancel a bounce if the player is holding bounce. 

Alternative: make the snap distance larger (e.g. 0.95) but only land on it if the drop ≤ 1 tile... For a 1-tile step-down: the ball at the edge, its bottom at y=13 (say), the lower surface at y=14 → probing 0.95 finds nothing (need 1.0). Let's use snapDown = 1.0 exactly? Probing exactly 1.0 tiles: the ball moves down 1.0 → overlaps the tile whose top is at 14 → overlap depth = (b.y+R) - ty where ty=13 (the tile row 13 contains y from 13 to 14): ball bottom after probe = 14.0 → floor(14.0 - EPS) = 13 → tile 13 is solid? In the case of a step down, the region below the ball past the ledge edge: at x=13.5, y=13..14 is empty (that's where the ball would fall through) — hmm wait. Let me set up: ground column x=12 has solid rows 13,14 (surface at y=13), and the next column x=13 has solid rows 14,15 (surface at y=14, i.e., 1 tile lower). The ball rolls right at y=12.5 (bottom 13.0) and passes into column 13. Now the tiles overlapping the ball's box x∈[13,14], y∈[12,13] → tile (13,12) not solid, (13,13) not solid (col 13 has rows 14,15 only) → no collision → not grounded. Snap probe down 1.0: ball center 13.5, bottom 14.0 → overlapping tiles y from floor(13)=13 to floor(14-eps)=13 → tile (13,13) — not solid! Hmm, because the surface at y=14 is the top of row 14; the ball resting on it has its bottom exactly at 14.0 which touches but doesn't overlap tile row 14. So probing exactly 1.0 gives zero overlap → no snap. Probe 1.05: bottom = 14.05 → floor(14.05) = 14 → tile (13,14) solid → overlap depth 0.05 > EPS → resolve y = 14 - 0.5 = 13.5 → grounded ✓.

So snapDown must be slightly more than the max step-down distance. Set snapDown = 1.1 → handles drops up to 1.0 tiles ✓ but not more. However there's a risk: when rolling off a real gap edge, a probe of 1.1 tiles could snap the ball down onto... nothing dangerous. But it also teleports the ball down up to 1.0 tiles in one step when the drop is ≤1.0 — that's the intended step-down behavior.

Wait, careful: `moveY(b, 1.1, true)` sets b.vy = 0 before the probe (I do that). If no hit, I restore b.y = ySave. But I also clobbered b.vy — the probe sets vy=0 only on impact (in land() when isProbe). Let me re-read: `land()` sets vy=0 for a probe. And in stepPhysics I set `b.vy = 0` BEFORE calling moveY — hmm, that kills the accumulated gravity velocity for that step even if no hit (I restore y but not vy). Let me restructure: save vy too and restore if no hit. Actually setting vy=0 before the probe then restoring both on failure:

```js
if (!b.grounded && wasGrounded && b.vy >= 0 && b.vx !== 0) {
  const ySave = b.y, vySave = b.vy;
  b.vy = CFG.snapDown / dt;   // hmm
  ...
}
```
moveY uses b.vy to compute the impact but takes `d` as the displacement; and on impact with isProbe, vy=0. So: save vy, set vy = 0? Then impact = Math.max(impact, b.vy) = 0 → `if (impact > 0) land(...)` won't fire! Because land() is only called when impact > 0. Ugh. With vy=0, a downward probe collision gives impact 0 → no landing → the ball's y is resolved (moved up to the surface) but grounded isn't set. Bad.

Fix: separate the probe handling from `land`. Let me rewrite moveY to take a mode: 'move' or 'probe', and detect a downward collision by `d > 0` rather than by impact velocity:

```js
function moveY(b, d, isProbe) {
  if (d === 0) return false;
  b.y += d;
  ... downward collision: b.y = min(...); 
      if (isProbe) { b.grounded = true; b.vy = 0; }
      else land(b, Math.max(b.vy, 0.0001));
      hit = true;
  ... upward: b.y = max; b.vy = 0; hit = true (ceiling)
}
```
Let me rewrite these functions cleanly. I'll rewrite the collision block:

```js
  /* returns true when the ball met something going down (a landing) */
  function moveY(b, d, isProbe) {
    if (d === 0) return false;
    b.y += d;
    const x0 = Math.floor(b.x - R + EPS), x1 = Math.floor(b.x + R - EPS);
    let landed = false, ceiling = false;
    for (let tx = x0; tx <= x1; tx++) {
      if (d > 0) {
        for (let ty = Math.floor(b.y - R + EPS); ty <= Math.floor(b.y + R - EPS); ty++) {
          if (isSolid(tx, ty) && (b.y + R) - ty > EPS) {
            b.y = Math.min(b.y, ty - R);
            landed = true;
          }
        }
      } else {
        for (let ty = Math.floor(b.y + R - EPS); ty >= Math.floor(b.y - R + EPS); ty--) {
          if (isSolid(tx, ty) && (ty + 1) - (b.x - R) > EPS) { ... }  // BUG: b.x should be b.y
        }
      }
    }
  }
```
I did write `(ty + 1) - (b.y - R)` in the original. Good, no bug there. Let me now rewrite the whole collision + step section properly with an edit.

Also the landing impact should use the velocity before resolution (b.vy at contact), fine.

Let me also reconsider the snap: applying `land()` on a probe would trigger a bounce. So probes must not trigger the bounce response. And after a successful snap, the ball is grounded with vy=0, so the next step's gravity + landing produces the bounce. ✓

One more subtlety about the snap: the ball rolls along the ground; each step, the real moveY collision re-grounds it. So wasGrounded is true and grounded is true → the snap branch is skipped ✓ (condition requires !b.grounded).

Another subtlety: while airborne after a real bounce, if it passes over a step edge... grounded is false and wasGrounded was true on the step right after launch — but vy < 0 (rising), so the snap condition (vy >= 0) fails ✓.

Let me now rewrite that section. I'll replace from `/* returns the landing impact speed (0 when none) */` through the end of `stepPhysics`.

Also I want to fix `land()` signature.

Let me write the replacement.

Let me check the exact text in the file — probably the comment lines differ (I wrote a two-line for-loop in the up branch?). Let me read that region.

The oldText I supplied for the up-branch loop was written as a single line in the file. Let me read lines 280-300 exactly.

Now I can craft exact edits. The whole block from line 280 to 314 needs replacing. Let me use a single edit with the exact original text.

The first edit probably succeeded? No — if any edit fails, the whole call fails (I believe). Let me check the actual text near line 355.

I forgot the `b.vy = 0;` line in my oldText. Let me redo edits 2 and 3 (edit 1 also failed since the whole call is atomic — let me verify by checking whether moveY was changed). The read at offset 278 earlier showed old text; since the call failed atomically, nothing changed. Let me re-issue all three edits with exact text.

Now let's test the sim headlessly before writing the shell. I'll write a node test harness that loads game.js (the sim part; the `/* __APPEND__ */` marker and no DOM code yet — the shell will be guarded by `typeof document !== 'undefined'`).

Test 1: basic physics sanity.
- bounce height from standing = 3 tiles.
- bounce height at full speed = 3 tiles, distance > ...
- friction stop time ≈ 0.5s.
- wall clear from standing.

Let me write /tmp/gen/test1.js:

```js
const fs=require('fs');
const src=fs.readFileSync(process.argv[2]||'game.js','utf8');
const B=new Function(src+'\n;return B;')();
```
Wait: game.js declares `const B = (function(){...})();` — inside `new Function` body that's fine, and returning B works.

Then run tests. The sim has run.screen='title' initially; call B.startRun() → screen 'play' but lock... lock doesn't block physics (only used by shell for screen transitions) ✓.

Test: place ball at spawn, hold bounce for a few frames: measure the apex.

Since `B.input` is exposed and `B.step(B.DT)` steps once. Let me write helpers: `hold(keys, seconds)`.

Measure apex: track min y (up is -y). Start y=12.5, apex should be 9.5.

Test A: standing bounce. Set bounce=true, step until grounded again, record min y → rise = 12.5 - minY should be ~3.0 (discretized: with dt=1/120 the apex is slightly below 3: the discrete apex = 3 - (v*dt)²/(2*... ) ~ within 0.05).

Test B: roll at full speed for 1s with bounce held: measure rise (should still be ~3) and horizontal distance per hop.

Test C: wall clear from standing at x=13.4 (adjacent to wall x=14): hold bounce + right; check the ball ends up past x=15 on the ground (y=12.5).

Hmm, careful: with bounce held and right held, the ball bounces continuously while accelerating.

Test D: friction stop time from 6 t/s: expect 0.5s.

Test E: full playthrough with a scripted input program.

Let me write the harness and run tests A-D now.

Note: the harness lives in .session/ which exists already — that's probably a session dir; putting test files there is a bit odd but acceptable (it's not part of the game). Actually, maybe better to put test scripts in /tmp so the delivered directory stays clean. Let me move it to /tmp/bounce-test/.

The ball isn't moving at all. Why? `door.x = -1` — my `Math.min(door.x, x)` logic: door.x initialized to -1 so min stays -1. Bug: I initialized `door.x: -1` then `Math.min(door.x, x)` = -1. Need to init door.x to a big value. Fix: `door: { x: 1e9, ... }` and then min. Let me fix.

But more importantly: the ball doesn't move. Why? Possibly `B.step` doesn't run physics because screen isn't 'play'... `B.startRun()` → toTitle() then setScreen('play') ✓. Hmm, but the ball never moves even with 'r' held.

Oh! Look at `stepPhysics`: it uses `input` — the module-level input object. And `hold()` sets B.input.* — same object ✓.

Hmm, wait: maybe the ball IS dying and respawning? No, at spawn nothing lethal... Let's check `checkTiles`: the hoop grab check etc. Actually! The spawn is (3.5, 12.5) and there's a hoop at (6,12) etc. Nothing at spawn.

Wait — maybe `run.screen` is 'play' but `stepPhysics` throws? Then the exception would propagate and node would crash. It didn't.

Hmm, "D max speed reached = 0.000" after holding right for 3s. And "C friction from 6.00" — so in test C the ball DID have vx=6 before! Because test C ran after test B where... no wait, C calls startRun() then holds right 1s → v0 = 6.00 ✓ so it DOES accelerate. Then it stopped in 0.842s (a bit long but includes... hmm 6/12 = 0.5s; 0.842 suggests it was bouncing? Actually with bounce not held, the ball settles. Hmm 0.842 = the loop counted steps while vx !== 0 — 0.5 s expected. Unless the ball hit a wall and... no, hitting a wall sets vx=0 → loop ends. Hmm, maybe the ball bounced off... at x=3.5 rolling right for 1s → x ≈ 3.5 + ~3 = 6.5. Then friction decelerates. 0.842s is odd.

Then D: startRun, hold right 3s → vx = 0 at the end. That means the ball hit the wall at x=14 (its right face... the wall at column 14 spans rows 11,12; the ball at y=12.5 overlaps rows 12 ✓) → blocked, vx=0 ✓. That explains C too (in C, after startRun the ball rolled right for 1s and by then... hmm, C measured v0=6 at 1s, then the friction loop ran until vx===0 — if the ball hit the wall at some point, vx→0 immediately, ending the loop. That gives 0.842 s? No — the loop exits as soon as vx===0, which is exactly when the wall stops it. Hmm, so C's measurement is polluted by the wall.

So: rolling right 3 s from x=3.5 hits the wall at x=14 → the ball is stuck against the wall at x≈13.5 with vx=0.

Then A: standing bounce → rise = 0? The ball at spawn (3.5,12.5) is NOT grounded initially (grounded=false set by placeBall). Holding bounce for 0.02s: it falls (gravity) then lands → `land()` with input.bounce true → launches! But my A test did: `H.hold(B,{u:1},0.02)` = 2.4 steps → the ball barely falls; grounded false; then the loop steps 400 times but minY tracking starts... y0 = 12.5 and it should rise to 9.5 → minY should be ~9.5 → rise = 3. But it printed 0.000, meaning minY stayed 12.5 — the ball never went UP. It fell? minY = min(y) — falling increases y, so minY = 12.5 → rise 0. So the ball never launched.

So landing didn't trigger a bounce. Because in `land()`, the condition `input.bounce && impact > CFG.settleVy`: after the initial fall from rest, the impact speed after ~0.02s of gravity ≈ 0.37 < settleVy (0.8) → no bounce, settles ✓ correct.

So A's test methodology was wrong (I need to hold bounce while the ball is grounded, which happens every step — the ball at spawn rests on the ground, and each step: gravity gives vy = 0.183, moveY(0.0015) → collision → land with impact 0.183 < settleVy=0.8 → no bounce!).

That's a real gameplay problem: pressing bounce while standing still must launch the ball to full height. With settleVy = 0.8 gating the bounce, a resting ball can't bounce. Fix: the bounce gate should not depend on the impact speed. Rule: if bounce is held at any landing → full launch. The restitution/settle path applies only when bounce is NOT held. So:

```js
if (input.bounce) { b.vy = -CFG.bounceV; ... }
else { b.vy = -impact*REST; if (|vy|<settle) vy=0; }
```
But careful: the resting case — each step, gravity gives a tiny downward move → collision → land → if bounce held → launch ✓. Good, that's what we want.

But there's an interaction with the snap probe: the probe doesn't call land ✓.

Another interaction: while rolling on flat ground with bounce held, the ball hops continuously ✓ (each step: tiny impact → launch at full speed).

And with bounce held continuously, the horizontal max speed still applies ✓.

Also the squash/stretch on a resting launch: strength = impact/bounceV ≈ 0.016 → stretch = 0.06 (fine).

Now also: the impact for `land()` is computed as `Math.max(b.vy, 0.0001)` where b.vy includes gravity for this step — fine.

Let me also reconsider the settle threshold for the non-bounce case: 0.8 t/s → bounce apex = 0.8²/44 = 0.0145 tiles. Fine.

Now test E: the wall clear test had `B.input.bounce = false` and steering logic. Let me rewrite the tests properly:

E: place the ball at x=13.2 on the ground (y=12.5, grounded), hold bounce for the whole jump plus right, then check it lands past the wall.

Careful: with bounce held continuously, the ball keeps hopping; steering right in the air at 0.4*18=7.2 t/s².

Let me also fix the door.x bug.

Also: initial `grounded=false` at spawn means the ball falls 1 frame at the start — harmless. But the initial resting state: placeBall sets grounded=false, so at the very first step gravity applies → tiny fall → land → if bounce held, launch. Good.

One more important check: `run.lock` — does it block physics? No, only the shell uses it. OK.

Also `stepPhysics` has `const wasGrounded = b.grounded;` declared before `b.grounded = false;` — and the `b.wall = 0;` line. Fine.

Let me fix the two issues (door.x, bounce gate) and rerun.

My earlier successful edit inserted slightly different comment text than what I wrote in the failed attempt. Let me read the current land() body.

Now edit with the exact text (including the two-line edit for door.x — the door edit may have succeeded? No, atomic; check whether door.x changed). Since the call failed, nothing changed. Let me do both edits with exact text.

Also the `door.w = 1` and `door.h` computed as bottom-top+1 ✓, and `door.bottom = door.bottom+1` (world edge) ✓. But the door.h is computed before overwriting door.bottom — check the order in parseLevel:

```js
door.w = 1;
door.h = door.bottom - door.y + 1;   // hmm, I wrote door.h = door.bottom - door.top + 1;
door.bottom = door.bottom + 1;
```
Yes: `door.h = door.bottom - door.top + 1;` = 12-11+1 = 2 ✓ then bottom = 13 ✓. Good.

Now rerun t1 with fixed tests.

Progress. Observations:

1. Standing bounce rise = 2.952 ✓ (discretization; ~3).
2. Hop rises: 2.95, 2.95, then 4.95?! That last one is suspicious — a rise of 4.95 means the ball went much higher. Wait, `segTop` measures the min y over a segment; if the ball lands on a HIGHER surface, the "rise relative to 12.5" grows. In test B the ball was rolling right at 6 t/s from x=3.5, hopping: after ~2s it may have reached the wall at x=14 and gone over it, then landed on top of... hmm, or it climbed onto the wall top (row 11, top y=11) → the apex relative to 12.5 would be 12.5 - (11 - 3 - 0.5...) Let me compute: standing on the wall top (surface y=11), the ball center rests at 10.5, apex center 7.5 → rise relative to 12.5 = 5.0 ✓. So the 4.95 is because the ball hopped onto the wall top. Not a bug ✓ (rise measured from a fixed baseline).

So B confirms: rises are equal while on flat ground (2.95 = discretization) and hop lengths ~3.9 tiles at 6 t/s. Good: 3.9 tiles per hop at max speed.

Hmm, hop length 3.31 then 3.91: at 6 t/s, a full hop should be v*T where T = 2*v_y/g = 2*11.489/22 = 1.044 s → 6.27 tiles. But measured 3.9. Why? Because I only held right in the air? No, I set `B.input.right = true` every step — on the ground the ball keeps accelerating to 6 ✓. Hmm, so why only 3.9?

Oh! The hop apex rise measured 2.95 relative to the baseline 12.5 — but if the ball is hopping on flat ground, the airtime is 1.044s → 6.27 tiles. Measured 3.91. Something's off: maybe the landings happen earlier because... Let me think: `prevVy < 0 && b.vy >= 0` detects the apex→descent transition, NOT the landing! So landX recorded the apex position, and my spans are apex-to-apex... which should also be ~6.27. Hmm.

Wait: apex detection: prevVy<0 && vy>=0 happens at the apex. And segTop tracked min y over the segment → apex ✓. apex-to-apex distance = v * T (T between consecutive apexes = full hop period) = 6.27 at 6 t/s.

Unless the ball was NOT at 6 t/s during those hops: after crossing the wall etc. Let me print more info: only the first two hops after starting at x=3.5 rolling at 6 with the wall at x=14 — the first apex is 3.31 tiles after the start of hopping, and the ball travels 3.91 to the next apex... Hmm, but the second apex (rise 4.95) is on top of the wall — the wall is 2 tiles up, so it lands on the wall top, and the wall slows it? No, vx preserved.

Hmm, let me reconsider: maybe my apex detection triggers twice per hop? After a bounce launch, vy = -11.489; at apex vy crosses 0 — but with discrete steps: vy goes ... -0.1, +0.083 → triggers once ✓.

Hmm, but there's another transition: on landing, `land()` sets vy = -bounceV (negative). Before landing vy was positive; after the launch vy is negative. So the sequence per hop is: launch (vy<0), ..., apex (vy crosses 0 → detected), descent, land (vy→ negative again). So detection = 1 per hop ✓.

Then apex-to-apex should be ~6.27 tiles at 6 t/s... unless the hop period isn't 1.044s. Let's compute the discrete trajectory: vy_{n+1} = vy_n + g*dt, y_{n+1} = y_n + vy_{n+1}*dt (semi-implicit Euler: moveY uses the updated vy). Launch vy0 = -11.489. Airtime until y returns to the start: with semi-implicit Euler, T ≈ 2*v/g ≈ 1.044s but slightly different. Then 6*1.044 = 6.27.

Unless... the ball was moving slower. Let me print b.vx at each apex. Also note in test B, after 0.8s of rolling from x=3.5, the distance covered is 0.8*... accel 18 → reaches 6 in 0.33s; total distance ≈ 0.5*18*0.33² + 6*0.47 = 0.98+2.82=3.8 → x≈7.3. Then 2s of hopping at 6 t/s = 12.5 tiles → x≈20 — that crosses both walls (x=14 and x=21!). So the ball is bouncing onto/over walls; the measurements are polluted.

Let me redo test B cleanly on the flat opening: put the ball at x=2, roll right for 0.6s (reaching max speed within x≈4.5), then hop for 1.6s (landing at x≈4.5+6.3=10.8, still flat) — measure the first 2 hops only.

3. Test C: friction stop took 1.225s and the ball hit the wall (`no wall hit: false`). The ball rolled for 0.6s (x ≈ 2.5) then friction decelerated it over 0.5s covering 1.5 tiles → x ≈ 6.5 — that shouldn't hit the wall at 14. Hmm! Unless the ball was hopping... no bounce held. 

Wait: why is the friction stop 1.225s? 6/12 = 0.5 s. Unless the ball left the ground and friction stopped applying... The ball rolls off the... hmm, x from 3.5: after 0.6s: ~3.8 tiles → x≈7.3, y=12.5 grounded. Then friction: 0.5s → +1.5 → x≈8.8. Total time to stop should be 0.5s. Measured 1.225s.

OH WAIT. I see: in test C I called `while (b.vx !== 0 && t < 2) { B.step(B.DT); t += B.DT; }`. But `B.step` → `run.lock` decrement etc. Physics uses `input` — but I never cleared the input keys! `H.hold(B,{r:1},0.6)` sets right=true, and the while loop just calls B.step without clearing keys → right stays held → the ball keeps accelerating → it never stops... until hitting the wall at x=14 which sets vx=0 ✓ → loop exits at 1.225s. That explains it. Same for the earlier note.

So test C is invalid. Fix: clear keys before measuring.

4. D: air accel 7.16 ≈ 7.2 ✓ (discretization).
5. E ✓ standing bounce clears the 2-tall wall (landed at 18 — hmm, that's 5.6 tiles from 12.4, and it landed past the wall at x=14. It says landed at x=18.02 — because with `bounce = b.grounded` it hops again? No: the loop breaks when grounded && x>15.6. It landed past the wall at x=18... but that means it flew from 12.4 to 18 in one hop = 5.6 tiles ✓ (it had air-steering the whole time, gaining speed). Fine — clears the wall at 14 ✓ and lands past 15.6 ✓. Also this means it may have flown into the wall at x=21? No, x=18 < 21.
6. F ✓ rolling into the wall without bounce stops at x=13.5 (can't pass without bouncing).

Let me rewrite the tests properly with input clearing. Also add:
- hop-length-vs-speed test: compare a slow hop (vx≈2) vs fast hop (vx≈6) → same rise, different length.
- the "no height from speed" test: max rise with bounce held from standing vs at full speed (both ≈3 relative to the launch surface).

Then the big playthrough test. Let me write test 2 with clean helpers: a function to run a scripted sequence of (keys, duration).

Let me also now design the playthrough script. I'll write it as a list of phases, tracking positions, and assert: no death (screen stays 'play'), all 6 hoops collected, crystal, both checkpoints, then completion.

I'll iterate on it interactively.

Actually, a smarter approach for the walkthrough: a small **autopilot** that follows simple rules (hold right; bounce when a solid obstacle/hazard is within N tiles ahead, or when a hoop is above). That would be much easier to write reliably than hand-tuned timings, and it doubles as proof that a competent player can do it. But designing a good autopilot takes effort. 

Middle ground: hand-tuned phases with position-based triggers, e.g.:
```
phase({until: () => ball.x > 12.0, keys: {r:1}})
```
and for jumps: "hold bounce while a condition holds". Let me define a tiny DSL: run a sequence of rules, each with `keys` and `while` predicate + timeout. That way, jumps are triggered by position and released on landing, robustly.

Simplest robust autopilot:
- Always hold right (except during specific backtracking for the crystal).
- Compute `needBounce()`: true if within lookahead the ball will collide: i.e., there's a solid tile at (floor(x+0.6+vx*0.15), floor(y)) row ahead OR a spike tile in the lethal-ish path ahead within 1.2 tiles, OR the ball is grounded and we want to keep hopping.
- Hold bounce whenever grounded and `obstacleAhead` → gives a full hop at the right moment.
- Also hold bounce while airborne if we want to keep hopping (needed for crossing spikes at distance)? Since bounce is applied only on landing, holding bounce continuously makes the ball hop at every landing; that's the "keep bouncing" behavior. The risk: hopping when a hop is wrong (e.g., bonking a ceiling). Not much ceiling here.

Let me write the autopilot with these rules:
```
obstacleAhead = isSolid(floor(x + 0.55 + 0.10*vxSigned), floor(y)) || spikeNearAhead
hoopAbove = a hoop exists with |hx - x| < 0.55 and hy < y - 0.6   → bounce to grab
```
And bounce when grounded && (obstacleAhead || hoopAbove || gapAhead).
gapAhead = the tile below-and-ahead (floor(x + 0.6), floor(y + 0.6)) is not solid and there's no support within 1 tile → i.e., the floor ends. To cross the pit, the ball must be airborne before the edge; the pit has spikes at the bottom, so spikeNearAhead should trigger earlier. Let me define hazardAhead: any spike tile whose x-range is within [x, x + 2.2] in the direction of travel and whose y is within [y-1.5, y+2.5]. Then bounce when grounded && hazardAhead → hops at ~2 tiles before the spike... The hop apex at 3 tiles means it clears the spike comfortably. But it must land beyond the spike: hop length depends on speed. At 4-6 t/s the hop is 4-6 tiles long. If it takes off 2 tiles before a spike, it lands 2-4 tiles past ✓.

For a spike pair, take off before the first one and land after the second ✓.

Also the ball must collect 6 hoops: hoops at height y-2 above the ground need a bounce. `hoopAbove` handles it: when grounded and a hoop is within 0.6 tiles horizontally and above, bounce (grab mid-flight).

Also hoops at y=10 while the ball is at y=12.5: |hy - y| = 2.0 → within reach (rise 3) ✓.

The crystal detour (x=41.5, y=8.5) is at height 4 above the ground: needs the stepping stone at (37, rows 11-12, top y=11). Autopilot: when near x≈36 on the ground, deliberately hop onto the stone (its top is 2 tiles up), then hop right onto the ledge, grab the crystal, then drop off the right side and continue right. I can script this portion explicitly:
- Phase 1 (autopilot) until x > 35.
- Phase 2 (scripted): hold right until the stone is close; bounce on it... still positional. Hmm: hop onto the stone at x=37 requires taking off around x=35.5 (rise 2 needs to happen before crossing x=36.5): at speed 3-4 t/s... Let me do: `while (x < 35.9) {r}` then `{r,u}` until grounded again with x>37.5 → the ball should land on the stone top (y=10.5). Careful: the spike is on the stone at (37,10)! Lethal box x ∈ [37.22, 37.78], y ∈ [10.25, 10.80]. Landing on the stone at x≈37.5 = death! So the ball must land on the stone at x < 37.22 - 0.5 = 36.72 or x > 38.28. Ugh — landing on the stone safely means landing on its left edge (x ≈ 36.5, i.e. right at the stone's left edge, ball center ≥ 36.5 (stone starts at x=37 → ball center must be ≥ 37 - 0.5 = 36.5) and ≤ 36.72 → window [36.5, 36.72] — that's 0.2 tiles! Way too tight, effectively frame-perfect. Or land on the right side x ∈ [38.28, 38.5] (the stone spans x 37..38 only, so the right edge is x=38 → ball center max 38.0 → no room!).

That's a design flaw: the stepping stone is 1 tile wide with a spike on top. That means it's basically unusable as a stepping stone — it's a spike hop.

Fix options:
(a) Make the stepping stone 2 tiles wide with the spike placed to the LEFT of the stone, not on it. But the spike on the stone was meant as difficulty.
(b) Move the spike off the stone (e.g., the spike sits on the ground at x=36 or so, in front of the stone), so the stone is clean and you hop onto it (needs clearing the spike... hmm).
(c) Remove the stone spike; keep the stone clean; keep the pit spikes as the main hazard, and the spike gauntlet after CP2 as the hardest.

I'll go with (c) plus: place a spike on the ground at x=35.5? No — the ground near x=35 is the landing zone after the pit; leave it clean.

Actually a nicer difficulty for the detour: put the spike on the ground at x=38 (right below the ledge, between the stone and the ledge)? Hmm.

Simplest: the stone at (37, rows 11-12) is clean. The detour difficulty = the hop from the stone to the ledge, plus the drop back. Keep the spike count reasonable: 6 spikes (2 pit + 4 gauntlet).

Alternatively, to make the stone interesting: put the stone at x=37 with a spike on the ground at x=38 (right at the base of the stone's right side)? That doesn't add much either.

Let me place the spike in the *detour landing zone* to make it a real risk: the ledge (x=39..43, row 9) — the ball must land on it. Below is the ground; if the ball undershoots from the stone, it just falls to the ground safely (no death) ✓ forgiving. So the detour is: hop to the stone, hop to the ledge, grab the crystal, drop off the right edge at x=43+ to the ground. Nice and forgiving, with the risk being the 4-tile drop (harmless).

To give the detour some bite, place a spike on the ground right under the ledge's left edge (x=38) so a failed hop that clips the ledge's left side and drops lands on a spike? Hmm, that's a "blind drop onto a hazard" — the spec forbids blind drops onto hazards. Skip. Keep it clean.

So: remove the spike at (37,10). 6 spikes total: pit (30,14),(31,14) + gauntlet (48,52,56,57).

Let me also double check the pit spikes are fair: the gap crossing is over spikes at the pit bottom. If you land short, you die — that's the classic gap hazard, visible before you jump ✓ not blind.

Hmm, is the crossing fair? The pit opening spans x=30..33 (rows 13,14 open). The spike lethal boxes at x ∈ [30.22,30.78] and [31.22,31.78], y ∈ [14.25,14.80]. To cross from x=29 (ground edge, right face of the ground at x=30) the ball must land on the far side at x ≥ 33 → wait, the far ground starts at column 33 → its top surface y=13; the ball's center must be ≥ 33 - 0.5 = 32.5 to land on it ✓. So the flight: takeoff from around x=29.5 (ball center; but the ground ends at x=30, so the ball can roll to center x=30.0 and beyond it starts falling).

Let me reason: the player rolls right at ~5 t/s; the ball leaves the ground edge at x=30 and must not descend below y=13 (bottom) before x=32.5... it must land on the far edge, i.e., at x≥32.5 with bottom ≥ 13. If the player holds bounce while grounded near the edge, the ball takes off at full height ~at x=29.5-30, giving 5*1.044 = 5.2 tiles → lands at x≈35 ✓ well past. If the player doesn't bounce, they fall into the pit (2 tiles) and die on the spikes (unless they land on the shelf at x=32 which is safe... x=32: the pit bottom row 15 solid at column 32 → the ball resting there has center x ∈ [32.5, ...]; hmm at x=32.5 the ball's bottom is 15.5... let me not worry: pit death is a fair failure).

Difficulty check: crossing 3-tile gap at ≥4 t/s ✓ generous.

Now let me also double check the spike gauntlet jump distances. Ground spikes at 48, 52, 56, 57 with lethal x-ranges [48.22,48.78], [52.22,52.78], [56.22,56.78], [57.22,57.78]. A hop at 5 t/s = 5.2 tiles. The player holds bounce while rolling right → continuous hops of 5.2 tiles each; landing spots depend on the takeoff phase. That's the risk: landings could be near a spike. Landing spots are 5.2 tiles apart; if one landing is at 51.9 (safe, 0.3 before the spike's lethal box at 52.22) that's tight. Hmm. This is the "hardest stretch" so some risk is OK — but "no obstacle that has to be taken at exactly one speed" and "nothing frame-perfect".

The player can control this by modulating speed: e.g., roll slowly and hop over each spike individually: a slow hop (2 t/s) has a length of 2.1 tiles — take off 1 tile before the spike (x=47), land at x≈49.1 (safe, past the spike's box at 48.78 by 0.3)... hmm also tight-ish.

Let me reconsider the spike hitbox: my x-inset is 0.22 per side → the lethal width is 0.56 tiles. If a landing happens exactly between two spikes... 

The safer design for the last stretch: spikes spaced 4 tiles apart (48, 52, 56, 57 pair). The pair at 56+57 has a combined lethal span [56.22, 57.78] = 1.56 tiles.

A competent player will bounce from ~1.5 tiles before each spike and land ~2.5-4 tiles after it, depending on speed. The window: to clear a spike at x=48 (lethal to 48.78), taking off at x=t0 and landing at t0+L (L = 1.044*vx), the ball's bottom must be above y=13 while over the spike, which is satisfied if the apex covers it: the ball's bottom is above y=13 (rise ≥ 0 from takeoff at 12.5 bottom=13.0; hmm, the takeoff bottom IS at 13.0, i.e. the same level as the spike's surrounding floor). Wait — the ground surface is y=13 and the spike's lethal box spans y ∈ [12.25, 12.80]. So the ball resting on the ground has its bottom at 13.0, below the lethal box's top (12.80)? No: y increases downward. The ball's bottom is at y=13.0; the lethal box's bottom edge is y = 12.80 < 13.0. So the resting ball's bottom (13.0) is BELOW the box (which ends at 12.80) → no overlap ✓ (a resting ball next to / at the spike's x-range doesn't touch it, but its bottom is at 13 which is past the box). 

Hmm! Wait: that means a ball rolling along the ground on top of a spike tile does NOT die?! Let's see: rolling at x=48.5, y=12.5 → box [48,12] to [49,13]; the spike lethal box is [48.22, 12.25] to [48.78, 12.80] → the ball's box overlaps in x ✓ and in y: ball y ∈ [12.0, 13.0], spike y ∈ [12.25, 12.80] → OVERLAP ✓ dead. Right — the ball's box spans 12..13 and the spike box is inside that range. Yes it dies ✓. Phew.

But it means: to be safe while passing over the spike x-range, the ball's bottom must be above 12.25, i.e. a rise of 0.75 tiles from the resting bottom (13.0). Rise ≥ 0.75 requires... from launch, the rise exceeds 0.75 at t: 0.75 = 11.489t - 11t² → t ≈ 0.0716s (and until t≈0.97). So during a full hop, the ball is safe over the spike for 0.9s of the 1.04s flight. The unsafe parts: the first 0.07s and last 0.07s of the flight → i.e., the ball must be at least ~0.4-0.6 tiles (at 6 t/s) away horizontally from the lethal box at launch and landing.

So a takeoff anywhere before the spike (outside the lethal x-range: x < 47.78 - 0.5 = 47.28 for the ball's left edge... let me define: the ball's x-span is [x-0.5, x+0.5]. To not overlap the lethal box in x, either x+0.5 < 48.22 → x < 47.72, or x-0.5 > 48.78 → x > 49.28.

So: at takeoff (t=0) the ball must be at x ≤ 47.72 or already past 49.28; and it must reach x ≥ 49.28 within 0.0716s... no wait: the requirement is that at every moment where x-0.5 ≤ 48.78 AND x+0.5 ≥ 48.22 (i.e. x ∈ [47.72, 49.28]), the ball's bottom must be above 12.25. So the ball must enter the x-interval [47.72, 49.28] (width 1.56 tiles) only while airborne above rise 0.75.

Take off at x0 ≤ 47.72 at time t=0. The ball enters the danger interval at t_enter = (47.72 - x0)/v and must have rise ≥ 0.75 by then → t_enter ≥ 0.0716 → x0 ≤ 47.72 - 0.0716*v. At v=6: x0 ≤ 47.29. At v=4: x0 ≤ 47.44. So takeoff must be ~0.3-0.4 tiles before... and it must exit at x ≥ 49.28 before landing: t_exit = (49.28 - x0)/v ≤ t_land - 0.07 = 1.044 - 0.07 = 0.974 → x0 ≥ 49.28 - 0.974*v → at v=6: x0 ≥ 43.4; at v=4: x0 ≥ 45.4.

So at v=6 the valid takeoff window for the spike at 48 is x0 ∈ [43.4, 47.29] — that's a ~3.9-tile window ≈ 0.65s of reaction. Very generous ✓. At v=4: [45.4, 47.44] → 2 tiles ✓ generous.

For the pair (56,57) the danger interval is [55.72, 58.28] (width 2.56): at v=6, x0 ≤ 58.28-... let me redo: enter at t_enter=(55.72-x0)/v ≥ 0.0716 → x0 ≤ 55.72 - 0.43 = 55.29; exit: (58.28-x0)/v ≤ 0.974 → x0 ≥ 58.28 - 5.84 = 52.44. So at v=6: x0 ∈ [52.44, 55.29] → 2.85 tiles ≈ 0.47s ✓ generous. At v=4: x0 ≥ 58.28-3.9 = 54.38 and ≤ 55.72-0.29=55.43 → window [54.38, 55.43] ≈ 1 tile ≈ 0.26s. So the pair needs a decent speed (5-6) for a wide window ✓ — that's "the hardest thing in the level" but not frame-perfect: at v=6 you have a 2.85-tile takeoff window (0.47 s). Good.

But careful: the spike at 52 is 4 tiles before the pair. If the player hops at each spike, the hop from before 52 lands... at v=6 a 5.2-tile hop taking off at 50 lands at 55.2 — that's inside the pair's takeoff window (52.44..55.29 for clearing the pair) but landing at 55.29+ would be too late (55.2 is just under). Landing at 55.2 is safe (the lethal box starts at 56.22, ball's right edge at 55.7 ✓ 0.5 clearance). Then from 55.2, the player needs to take off again within [52.44, 55.29] — they're at 55.2, still within the window ✓ (bounce immediately at landing). If they land at 56+ they'd die. So the landing after spike 52 must be < 56.22-0.5=55.72 ✓ and > ... a landing beyond that would have crossed the pair's box while descending... the landing must satisfy the same constraint (it's the same flight) — so if they cleared 52 and land at 55.5, they immediately bounce again ✓. But if they land at, e.g., 53.0 (lower speed), then they'd have to take off again before the pair: at v=4 the window was [54.38, 55.43] — they're at 53, and they keep accelerating; the takeoff happens at the landing (bounce held) → so with bounce held the takeoff is at 53.0 with v=4 → x0=53 < 54.38 → they'd enter the danger zone at t = (55.72-53)/4 = 0.68s, rise at 0.68 = 11.489*0.68 - 11*0.46 = 7.81-5.07 = 2.74 → hmm the ball is at rise 2.74 at entry ✓ safe, and exits at (58.28-53)/4 = 1.32s > landing time 1.044 → so the ball lands at x = 53+4.18 = 57.2 → INSIDE the pair's danger interval → the ball's bottom on landing is at 13.0 which overlaps the lethal box [56.22..57.78]x[12.25,12.8] → DEATH.

So: with bounce held continuously at 4 t/s the pair kills you. The player must either go faster (5-6 t/s) or take two hops. This is a fair "hard" section but is it fair? A player holding bounce and rolling right at max speed (6 t/s) clears everything: let me verify with the autopilot simulation. If at max speed the continuous hop lands the ball in bad spots, then the level is unfair. Let's check hops at v=6 (5.2 tiles): the takeoff positions matter. Let me simulate the sequence and see.

I'll test with the autopilot and iterate. The important thing: at max speed holding bounce continuously, does the ball survive the gauntlet? Landing points: the takeoff for spike 48 must be in [43.4, 47.29]. Landing points spaced 5.2 tiles. The gauntlet starts after CP2 at 44.5. So the player arrives at ~44.5 and starts bouncing. If a landing at ~46 then the next takeoff at 46 ✓ (in window), lands at 51.2 → clear of spike 52 (lethal 52.22; the ball's right edge at 51.7 ✓ safe). Then takeoff at 51.2 → window for spike 52's danger interval [51.72, 53.28]: x0 must be ≤ 51.72 - 0.43 = 51.29 ✓ (51.2 is just inside!) and ≥ 53.28 - 5.84 = 47.44 ✓. So takeoff at 51.2 clears spike 52 ✓, lands at 56.4 → INSIDE the pair's lethal zone (56.22..57.78) with the ball's box [55.9, 56.9] overlapping → DEATH. Hmm.

So blind max-speed bouncing may kill at the pair. But the player can adjust: they'd need to land between 51.72-... The landing must be at ≥ 58.28 + 0.5 = 58.78 to be past the pair, requiring a takeoff at 53.5+ (5.28 earlier). Since the landing after spike 52 is determined by the previous takeoff, the player can modulate: release bounce for one landing (settle), then hop from a chosen spot. Since landing-without-bounce settles quickly (0.6s, ~1.4 tiles of extra roll), the player can pick a takeoff spot: land at ~53 then tap bounce at the right moment.

Hmm, "nothing frame-perfect" — this gives a window; the takeoff for the pair must be in [52.44, 55.29] (2.85 tiles ≈ 0.47s at 6 t/s). But if you arrive at 51.2 having cleared spike 52, you need to land first and then take off in that window... When you land at 51.2 with bounce held, you immediately launch again. If instead you release bounce, you land and roll; then you press bounce somewhere in [52.44, 55.29] which at 6 t/s takes 0.47s. But careful: rolling through the danger interval [51.72, 53.28] of spike 52 while grounded — the landing at 51.2 means you were airborne; rolling from 51.2 to 51.72 (spike 52's left danger boundary) with the ball on the ground: the ball's box overlaps the spike's lethal x-range

Wait — row 12 now has ' ###' at x=36..38 but the spike at (37,10) remains in row 10 at x=37. That spike is now on top of the (37,11) stone — the stone is 3 wide so landing at 36.5 or 38.5 is safe. Good, that's what I intended.

Let me double check the widths are still 64. Row 12: originally `'#..@..o.......#......#....c..........#......co..S...S...SS...E.#'` → I replaced `..........#` (10 dots + #) with `......... ###` (9 dots + space + ###). Original segment from x=27: dots 27..36 (10 dots) then '#' at 37. New: 9 dots (27..35) + ' ' + '###' → ' ' at 36?? Wait I wrote 9 dots then a space then ### = the space is at index 36, which means x=36 is a SPACE not '.' — space isn't a recognized char, so it's treated as empty (my parser ignores unknown chars) ✓ but it's sloppy. Let me fix: it should be 8 dots + 3 '#'? Let's count what I want: ground dots at 27..35 (9 tiles), then '#' at 36,37,38, then dots from 39.

Original row 12 (index → char):
0 '#'
1-3 "..." (1,2,3) with '@' at 3 — let me just count the new string length and verify programmatically. Also check x=36,37,38 are '#' in row 12 and row 11.

Let me run a quick check.

Good — the validation caught the width error (that's what it's for). Let me fix row 12 properly by regenerating the whole map with the node generator to be exact, then paste.

Wait — the checkpoint 'c' at x=26 is in row 12 ✓ ("....c" region) and hoop 5 at 45, and note the stepping stone now occupies x=36..38 in rows 11,12. But hold on: in row 12, is the checkpoint at x=26 preserved? Looking at row 12: `'#..@..o.......#......#....c.........###.....co..S...S...SS...E.#'` — index: 0 '#', 1-2 '..', 3 '@', 4-5 '..', 6 'o', 7-13 '.......', 14 '#', 15-20 '......', 21 '#', 22-25 '....', 26 'c', 27-35 '.........', 36-38 '###', 39-43 '.....', 44 'c', 45 'o', 46-47 '..', 48 'S', ... ✓

Now replace the LEVEL block in game.js with this. Note that the earlier broken edit produced rows that need to be reverted; the safest is to replace the whole LEVEL block. Let me do that with python (replace between "const LEVEL = [" and "  ];").

My "unexpected chars" check string `"#SoC E@"` didn't include '.' — my own test bug, not a game bug. The map parses cleanly (problems: []).

Now let me write the autopilot playthrough test.

Plan the autopilot:
- Goal: collect all 6 hoops, both checkpoints, the crystal (detour), reach the exit.
- Rules while moving right:
  - If grounded and (obstacle ahead OR hazard ahead OR hoop above-near OR gap ahead) → hold bounce.
  - Also for the crystal: scripted phases.

Let me write it with explicit phases and use "hold bounce for N seconds from a trigger point".

Phase list (each: name, keys, until condition, timeout):

1. Roll from spawn: hold right until x ≥ 5.5 → passes hoop 1 at 6.5 (ground-level hoop, collected while rolling). Actually hoop 1 is at x=6 (center 6.5), y=12 center 12.5 → rolling at y=12.5 collects it ✓ within grab radius 0.95.
2. Hoop 2 at (10.5, 10.5): when |x-10.5| < 0.45 and grounded → tap bounce (hold until airborne > 0.15s). Collect mid-flight ✓.
3. Wall at 14: hold right; when grounded and solid ahead (x+0.8 within the wall) → hold bounce; keep bounce held while airborne? If bounce is held at landing it re-launches. To cross the wall: take off just before it. Let me use the rule: hold bounce when grounded && (solid ahead within 0.9 tiles || hazard ahead within 1.6). While airborne, release bounce (so landings settle) unless we need to continue hopping.
   But with the wall ahead, the takeoff at ~1 tile before the wall at low speed: the ball is rolling at up to 6 t/s. Hmm, if it takes off at x=12.9 (wall face at 14; the ball's right edge hits 14 → center 13.5; solid-ahead detection: isSolid(floor(x+0.9), floor(y)) → at x=12.9, floor(13.8)=13 → tile (13,12) is not solid; at x=13.05, floor(13.95)=13 → not solid; the wall column is 14, so detection triggers when x+0.9 ≥ 14 → x ≥ 13.1 — but at x=13.5 the ball's right edge already touches the wall face. So detection at x≥13.1 gives ~0.4 tiles (0.07s at 6 t/s) to launch. Since we bounce the same frame the condition is true, the ball launches from 13.1. Its rise then carries it up; the wall is at x=14 → moving right at 6 t/s while rising: at rise 2 (which happens at t=0.22) the ball is at 14.4 — its right edge at 14.9 > 14 but its bottom is at 10.8 (above the wall top at 11)? The wall top is y=11 (rows 11,12 solid) → the ball's bottom must be above 11 → rise ≥ 2 from 12.0 (bottom at 13 → the bottom is at 13 - rise; to be above 11 → rise ≥ 2). Hmm: at rise 2, the bottom is at 11.0 ✓ exactly at the wall top.
   
   Careful: moving horizontally into the wall while the bottom is below 11.0 → blocked. From takeoff at 13.1 (bottom 13.0) rising at 11.49 t/s: the bottom reaches 11.0 at rise 2 → t=0.22s (approximate with gravity: 11.489t - 11t² = 2 → t=0.22). In 0.22s at 6 t/s the ball moves 1.32 → x = 14.42 → its LEFT edge is at 13.92 < 14 → it's overlapping the wall column horizontally; the bottom is at 11.0 exactly at the wall's top edge → it's still "inside" the wall's column x-range [14,15] with the bottom at 11.0 = the wall's top face → no penetration (touching) ✓. As it rises more, it clears. But during the crossing, at t=0.15 the bottom is at 13 - (11.489*0.15 - 11*0.0225) = 13 - (1.72-0.25) = 11.53 → below the wall top (11.53 > 11) → and its right edge at 13.1+0.9 = 14.0 → it starts overlapping the wall column → the x-move gets blocked at x=13.5 (wall face minus radius) → the ball slides up the wall face until the bottom clears 11.0, then continues right ✓. That works (the classic "hug the wall and jump" behavior) — it costs some horizontal speed (vx is zeroed on the wall contact) — after clearing, the ball is at x=13.5 with vx=0 at height ~10, then it continues rising and falls, and the player keeps holding right, accelerating again → the ball lands on the wall top (surface y=11) if the apex gives enough time. From y=10 (bottom at 10.5, above 11 ✓) with vy small: it will drift right and land on the wall top ✓ then roll off.

   Hmm, this "wall hug" is realistic for a player too. Fine.
   
   But it zeroes vx, which may cause the ball to land right at the wall's right edge... The wall is 1 tile wide; landing on top of it is fine.

   Let me just run it and see.

4. After the wall, hoop 3 at (19.5,10.5): same as hoop 2. Then wall at 21 — careful: the wall at 21 is 5 tiles after 14; landing after rolling off the wall top... fine.
5. Continue right past CP1 (26.5 → collected automatically, grab radius 1.0) and cross the pit: hazard ahead → bounce. The pit spikes are at (30,14),(31,14) with lethal boxes y ∈ [14.25,14.8]. The ball rolling at ground level y=12.5 (bottom 13.0) — the "hazard ahead" rule should trigger a bounce before x=30. My hazard rule: spike exists with spike.x within [ball.x, ball.x + 2.0] and |spike.y - ball.y| ≤ 2 → at x=28, the spike at x=30 is within 2.0 ✓ → bounce. Good: the takeoff at x≈28 lands ~5 tiles later at 33 ✓ (or 3.3 at 4 t/s → lands at 31.3, descending... need to be above 13.0 bottom until x≥32.5).

Hmm, landing at 31.3 with the bottom at 13 means it descends into the pit region while its bottom is above 13 until x=31.3? A landing at x=31.3 means the ball's bottom reached y=13 at x=31.3 — but there's no ground at x=31.3 (rows 13,14 are open) → it doesn't land there; it continues falling into the pit → then it hits the spike box or the shelf. So an under-speeded jump falls into the pit → death → but wait, if it doesn't land it will keep falling past y=13 into the lethal boxes at [14.25,14.8] at x∈[30.22,30.78] or [31.22,31.78]. Falling at x=31.3 → the ball's box x ∈ [30.8, 31.8] overlaps the spike box at [31.22,31.78] ✓ and its y range as it falls passes through [14.25,14.8] ✓ → death.

So crossing requires enough speed: takeoff from x=28 → the ball must reach x=32.5+ while its bottom is above 13 (i.e., within the first 1.044s) → 4.5 tiles in ~1.0s → v ≥ 4.5 t/s. Rolling from CP1 (x=26.5) with an obstacle-free run: at CP1 the ball is likely already at 6 t/s from earlier rolling ✓. Also the bounce trigger at x=28 with v=6 → lands at 33.5 → on the far ground (needs x ≥ 32.5 ✓) but careful: it lands where the ground exists; if it descends past y=13 at x=32.9 (center 32.9 → its left edge at 32.4, over the pit; the ground column 33 starts at x=33 → the ball's bottom would pass 13 without landing... Let me not over-think: the x-collision resolution handles it; the ball can also hit the right wall face of the pit? No, at x=33 the pit's right side (column 33 rows 13,14 solid) face is at x=33 → the ball entering the pit region would hit that face at center 32.5 and slide down to the pit floor → death by spikes if it slides into them (at x=32.5 its box spans 32..33 → the spike box at [31.22,31.78] doesn't overlap ✓ safe) → it lands on the shelf at x=32.5 safely, then can bounce out (rise 3 clears the ledge at 13 from the pit floor 15? The shelf is at the pit floor y=15 (row 15 top). Rise 3 → bottom 12 → clears 13 ✓ and it can move right onto the ground ✓ (the wall face is at x=33 for rows 13,14 — while above 13 the ball can move right ✓).

So even a failed crossing at x=32.5 is recoverable ✓, but landing at x=31 dies. That's the "one gap floored with spikes" ✓ fair, visible, with generous speed room at 6 t/s.

6. After the pit: hoop 4 at (34.5,10.5) — right after landing at ~33.5, the autopilot's "hoop above near" rule should bounce when |x-34.5| < 0.45.
7. Crystal detour: scripted — at x≈34.5 (after grabbing hoop 4), bounce onto the stone... the stone top is at y=11 (rows 11,12 solid at 36..38), so the ball must land at y=10.5 on the stone. Take off around x=35 → hmm, the ball needs to rise 2 tiles while moving right ~1.5 tiles. At 6 t/s the ball crosses x=35.5 (the stone's left edge + radius = 36.5 for landing) — the ball's bottom must be above 11 when crossing... it'll hug the stone face and ride up ✓ same as the walls.

   Simpler: the autopilot just holds right+bounce while grounded until it's past x=38.5 → it should end up on top of the stone, then continue right onto the ledge (row 9, top y=9 → 2 tiles above the stone top) → again hug-and-ride ✓. The ledge spans 39..43 (5 wide) → landing on it is easy. The crystal at (41.5, 8.5) gets collected while walking on the ledge (the ball's center at (41.5, 8.5) exactly when on the ledge ✓).
   Then drop off the right edge at x=43.5 → falls 4 tiles to the ground (y=12.5) → lands at x≈44-45 → CP2 at 44.5 ✓ + hoop 5 at 45.5 (ground level) ✓.

   Careful: falling 4 tiles onto the ground at x≈44.5 — but the spike at 48 is 3.5 tiles further, fine.

8. Gauntlet: hold right; bounce when a hazard is ahead within ~2 tiles. Need to verify all 4 spikes are cleared. As computed, the takeoff windows are generous at 5-6 t/s.

9. Final: reach the door at x=61 → complete.

Additional subtlety: after landing on the stone/ledge and dropping, the ball's speed may be low; the gauntlet needs speed. The autopilot holds right so it accelerates.

Let me now write the autopilot as: a function `decide(state)` returning keys, plus a step budget. Track deaths (should be 0). If it dies, the harness logs where.

Then a separate harness test: die 3 times → Game Over → title fresh; checkpoints bank; score math; frame-rate determinism.

Let me write the autopilot file.

Note: `S.checks` — is the checks array on the state? The state `run` has `checks`? No: `L.checks` (level). In my test I used `S.checks` — need `L.checks`. Let me fix when running. Let me just run and fix errors.

The autopilot died at x≈36.7, y≈10.5 — that's on the stone... y=10.474 means the ball's center is 10.47 → resting on the stone top (y=11) would be 10.5. x=36.74 → the spike at (37,10) has a lethal box x ∈ [37.22, 37.78], y ∈ [10.25,10.80]; the ball's box at x=36.74 is [36.24, 37.24] → overlaps 37.22-37.78 by 0.02 → DEATH.

Hmm! Because the ball's right edge at 37.24 grazes the spike box. The ball is standing at x=36.74 (it was blocked by something? no). Also the deaths: 1 death. Where? Let me trace. Note "hoops left: 3" and it collected hoops 1,2 (x 6.5, 10.5) and one more? And checks: first collected, second not.

So it died at the stone because it stopped there with the spike too close. The stone is 3 wide (36..38): valid standing positions without touching the spike box (x∈[37.22,37.78], y∈[10.25,10.8]) → ball center x must satisfy x+0.5 < 37.22 → x < 36.72, or x-0.5 > 37.78 → x > 38.28. The stone spans x ∈ [36,39] (columns 36,37,38 → x from 36 to 39). The ball's center can be from 36.5 to 38.5 on the stone. So the safe standing zones are [36.5, 36.72] and [38.28, 38.5]. Both narrow! Landing anywhere in between = death. That's the frame-perfect trap I wanted to avoid — and it triggered exactly.

So a spike ON the stepping stone is bad design, period. Remove the spike at (37,10). Then the stone is clean.

But wait — it also says deaths:1 which happened there. And the "gap" detections at x=15 and x=21.8 suggest the ball was on top of the walls (rows 11,12 → below it at fy... the gap detector fires when the floor ahead isn't solid within 2 tiles: standing on a 1-wide wall top, the "floor" ahead is gone → 'gap' → bounce → OK, that's fine (it hops off).

Also I noticed: it reached x=28.4 (spike = pit) at 4.99s ✓ then at 6.04s it's at x=34.7 → so the pit crossing worked. Then the wall = the stepping stone at 36 ✓, then died at 36.74.

Let me remove the stone spike and rerun. Spike count then = 6 (2 pit + 4 gauntlet). That's fine (the spec doesn't fix the count).

Alternatively move the spike from the stone to the ground at x=35 (between the pit landing and the stone)? That could make the pit landing zone deadly: landing at 33.5 then rolling to a spike at 35 — hmm, the landing after the pit needs clear room per spec ("several clear tiles ... after every landing"). Don't add it there.

Just remove the stone spike.

Critical: game.js currently has NO browser shell — it ends with `/* __APPEND__ */`. So index.html loads but nothing renders. That's the one thing worth fixing: the game must render and be playable.

I have 5 minutes. Let me check the current state of game.js quickly, then append a working shell (rendering + input + loop) as compactly as I can. That's the priority.

Let me first check the file tail and syntax.

As feared: the sim module is complete and syntax-clean, but the browser shell (rendering, input, rAF loop) was never written — `index.html` loads a canvas that never draws. I must append the shell now.

I need it compact but correct. Let me write it replacing `/* __APPEND__ */`.

Shell needs:
- canvas get, ctx
- integer scaling on resize
- input keydown/keyup with preventDefault
- screen transitions: Space on title → startRun; on complete → toTitle; gameover auto → title
- fixed-step accumulator loop
- render: tiles, spikes, hoops, checkpoints, crystal, door, ball, effects, HUD, screens

Careful about what exists in B: state (run) with fields screen, timer, lock, lives, score, finalScore, hoopsLeft, crystalGot, respawn, exitOpen, camX, ball{x,y,vx,vy,grounded,wall,airTime,rot,squash,stretch}, fragments[{x,y,vx,vy,life,size}], ring{x,y,t}.

level: L with W,H,rows,solid,spikes[{x,y}],hoops[{x,y,tx,ty,got}],checks[...],crystal,door{x,y,h,bottom},spawn.

CFG: radius, deathTime, gameOverTime, screenLock, scoreHoop etc, startLives, maxLives.

B.step(DT), B.startRun(), B.toTitle(), B.input, B.isSolid, B.TS, B.VIEW_W/H, B.HUD_H, B.spikeBox.

Note: run.lock is decremented in step; screen transitions on Space need `run.lock <= 0`.

Also note the sim doesn't auto-return from 'complete' (only gameover→title). Space on complete → toTitle.

Let me write it now, fast but careful. Keep colors flat.

Drawing order with translate(-camPx, 0). camPx = Math.round(run.camX*TS).

Text helper with ctx.font sizes in logical px.

Ball squash: sy = 1 + stretch - squash, sx = 1/sy, clamp 0.6..1.4. Draw ellipse via ctx.save/translate/scale/arc.

Let me write it.