Physics-driven game

# Build Prompt — Odysseus and the Cyclops

A single build. A real, playable 3D game of Odysseus' escape from the cave of Polyphemus
the Cyclops, from *The Odyssey*. Two phases, in order: **blind** the passed-out giant with a
burning stake, then **escape** the cave clinging to the underbelly of a ram while the
blinded Cyclops gropes for you. It has to look like a **2026 AAA game** and actually be
playable and winnable. Everything is generated in code.

---

You are a world-class real-time graphics engineer AND game developer. Build a
production-quality, fully playable 3D game using **WebGPU via Three.js (WebGPURenderer +
TSL)**, native ES modules, no build step. Build all geometry and materials procedurally in
code — no imported 3D models, no image textures, no HDRIs. You MAY use open-source
libraries for the hard plumbing: a physics engine (`@dimforge/rapier3d` or `cannon-es`),
post-processing passes, and `lil-gui`. But you build the Cyclops, the cave, the rams, the
stake, and every material from math.

## The game — two phases

**Setting:** the torch- and fire-lit cave of Polyphemus. A massive Cyclops, a flock of
rams, the great fire, and the sharpened olive-wood stake.

### Phase 1 — Blind the Cyclops
Polyphemus is passed out drunk on the wine Odysseus gave him.
- **Heat the stake** in the fire: a charge mechanic — the tip glows wood-brown → red →
  white-hot and casts its own growing light. Too cold and the thrust fails; hold too long
  and the Cyclops stirs toward waking.
- **Aim at his single eye and THRUST** (press-and-hold to heat + aim, release to drive it
  in). Model the stake as a real physics object with weight and momentum.
- **Feedback + states:** sparks, a bright flash, the Cyclops roars and rears up, the eye
  goes dark. Clean win/fail: too early = not hot enough (bounces off); too slow = he wakes
  = game over. Success flows straight into Phase 2.

### Phase 2 — Escape under the rams
Now blind and enraged, Polyphemus feels his way to the cave mouth and **gropes the BACK of
every ram** with his huge hands to catch anyone riding out.
- **Cling to the UNDERBELLY of a ram** — the trick from the myth: he feels the top, never
  underneath.
- Move the flock toward the cave mouth; let the player **switch rams** and **time their
  movement** so they're never under a hand that's sweeping their lane.
- His hands sweep the rams' backs with real reach and readable timing (clear tells). Get
  felt = caught = fail. Reach the daylight at the cave mouth = **win**.

## Realism bar — this is the whole test
- **The Cyclops must be a believable, properly-proportioned GIANT** — real head with one
  eye, torso, arms, legs, huge hands, PBR skin, correct scale against the rams and the cave,
  simple believable animation (sleeping breath, the rear-up, the blind groping). A
  **stick-figure or featureless blob is a fail**, same bar as the ship.
- **Fire-lit atmosphere:** the great fire + torches as physically-correct lights,
  noise-driven flame flicker, **volumetric light shafts / god rays**, emissive flames with
  bloom, the **white-hot stake casting its own moving light**, deep shadow, depth-based haze,
  drifting embers/dust motes.
- **PBR everything:** FBM / triplanar **stone** for the cave walls and floor, procedural
  **wool** on the rams, **wood-grain** on the stake, wet/greasy sheen where it belongs,
  ambient occlusion in every crevice.
- **Lighting + render pipeline (all named, all required):** IBL via **PMREM** (dim cave
  ambient), **cascaded shadow maps**, **SSAO**, **SSR** where useful, **ACES** tone mapping,
  **bloom**, **depth-of-field** on the cinematic beats, correct linear/sRGB color management.
- **Physics:** real rigid-body physics for the stake, the rams, and collisions (use the
  physics lib). **Continuous / swept collision** so fast motion doesn't tunnel.

## Feel & controls (make it play like a real game)
- **Phase 1:** press-and-hold to heat + aim, release to thrust; a subtle heat gauge; camera
  pushes in on the eye with shake on impact and a brief slow-mo on the hit.
- **Phase 2:** move/steer the ram, switch rams, a tension meter for how close a hand is;
  under-belly / over-the-shoulder camera.
- Clear HUD, win and lose screens, quick retry. **Web Audio (synthesized only):** fire
  crackle, the Cyclops' breathing and roar, the stake sizzle, hooves — no imported audio.
- A live **FPS** readout and a difficulty / assist toggle.

## Runtime handling (required)
WebGPU detection with a graceful message, loading and failure states, resize, touch +
keyboard input, capped DPR, hidden-tab pause, `prefers-reduced-motion`, accessibility, and
performance safeguards (LOD / throttling to hold a smooth frame rate).

## Standards & iteration — do not stop early
Judged on how real it looks AND how it actually plays. **Do not call it done until the
Cyclops, the cave, and both phases clear the realism bar and the game is genuinely playable
and winnable end to end.** After building, render it, screenshot your own output, and
inspect it — the giant in close-up, the fire lighting, both phases played through. If the
Cyclops reads flat, if the cave looks like noise, if a phase isn't actually playable — fix
it and go again. Minimum **three full self-review-and-improve passes**, more if needed. No
placeholders, no invented APIs, no console errors, no hidden fallback rendering.

## Deliverable
Complete, directly runnable code (index.html + JS modules + any pinned library imports) plus
brief launch instructions. It must run at a smooth frame rate, look like a modern game, and
be fully playable and winnable.