Platformer improvement pass: L7 undercroft puzzle, second checkpoints, scene density, coin tiers, audio + win polish

[SethMorrowSoftware]

What this is

A deep review of the platformer demo (seven parallel readers mapped every level, maker, tick and event path against CLAUDE.md's laws and the polish plan), followed by an improvement pass built with the proven methods: append-only growth, existing makers only, every placement checked against the ~100px beat-air law, all example-side (no Kit change, no harness bump, kPfUIVersion untouched).

The headline: the L7 UNDERCROFT (length + the missing puzzle)

The Stone Keep grows down 512px (pfBoundsV bottom 2304 → 2816) into a torchlit vaulted undercroft — Phase C slice 3's multi-key/switch puzzle finally lands in the keep, where the file header always said it belonged:

• You spawn in the vault. The old ground line became the keep floor with a 128px trapdoor doorway (the only way up — the gate is structural, wall to wall).
• A blue switch in the far-right corner (past a warden slime, lit by a wall torch) slides the blue lid aside above you; three vaulted one-way ledges climb to the doorway; a checkpoint on the keep floor holds progress.
• To make it possible, pfMakeSwitchGate/pfTickSwitchGates were generalized vertically aware — per-instance pad band (the old tick hardcoded the 448-cloud band and silently ignored pSwitchY, a latent bug), per-instance gate rect, slide axis, open-shift. L2's green-gate call is byte-identical (walked through with its exact arguments). pfMakeCheckpoint now banks a per-flag respawn height (uPfCheckY; the touch handler hardcoded 470 — mid-air on a tall world).
• The lid slides right deliberately: parking left would sit it 64px under tower ledge 1, the gotcha-20 one-way straddle trap. The ledge/blade/warden geometry above the keep floor is untouched.
• No tiles art (gToysOK false) = no lid: the doorway stays open and the climb completes (law 25).

Since tools/audit-platformer.py skips vertical levels, the undercroft geometry was hand-verified by a 32-check script (squeeze clearances, jump rises, gotcha-20 for both lid park positions, pad-vs-patrol bands, structural-gate coverage, camera clamps).

The rest of the pass

• Second checkpoints on the long single-checkpoint levels — the review found the difficulty ramp inverted by punishment (L1–L4 ran 3,400–4,700px past their lone flag): L1 5500, L2 5230, L3 5180, L4 4860 (paired with the way-marker sign).
• Scene density, by eye (polish plan §3, the Clocktown lesson): a few strong reads per level from already-loaded frames — L1 pool-finale dressing, L2 spawn/works/vault (torch + windows), L3 (the barest level) citadel finale, L4 hanging chains + cave torches, L5 dune cacti, L6's torch dark-zones lit. Three live placement conflicts fixed (L2 alley sign stood inside the slice-3 gate wall — retired, no legal pocket exists; L2 bush off the barnacle's snap zone; L3 sign off the snail's patrol).
• L6's orphaned second bat roost gets its bat — with its band deliberately ending short of the G4 cloud's chain (bats swoop to y~450; the chain sits at 448 — a band over the cloud would grind the velocity assert against the chain, gotchas 17/18).
• Deliberate coin tiers: L7 explicit everywhere (the auto height rule paid bronze for the hardest mid-shaft gap grabs on a vertical world); marquee grabs go gold on L4 (serpent stone), L5 (dune crest), L6 (star cloud).
• Audio (§5): a distinct star fanfare (was sharing the gem chime — an admitted "for now"), a five-note final-win fanfare, and the orphaned creak tone finally wired to rope-bridge landings. Newest-cue guard re-keyed to fanfare.
• Win payoff (§6): hits banked across the run (gOuchesBank), an UNTOUCHABLE callout tier above flawless, a hidden-star replay tease.
• Fixes: the L7 build-frame 64px camera snap (narrow worlds now frame their centre, matching the per-frame clamp); the stationary half-blade's per-frame same-loc b2kSpriteMoveTo skipped (write-on-change); L3's stale lever-saw binding removed; b2kSensorEnter's hazard branch gains its missing exit (verified behavior-neutral — no sensor carries both flags); stale comment sweep.

Verification

• python3 tools/check-livecodescript.py — all pass.
• python3 tools/audit-platformer.py — 0 findings across 7 levels (it caught one of my own placements mid-pass — an L2 sign overlapping a coin — which is why that sign is retired).
• Undercroft geometry script — 32/32 checks pass.
• Verified statically; needs an OXT pass. The in-file header's item 21(i) lists the exact OXT verify items for the undercroft (bonk-not-squeeze at the closed lid, the latch + slide, the checkpoint respawn height, the fallback open-run, tier reads).

🤖 Generated with Claude Code

https://claude.ai/code/session_01B6aG88HWGdnCw7qhEUuZkj

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Generated by Claude Code