A game here

PixiJS 8.21 (v8 API only). Never guess an API: load the skill pixijs (it routes to the right pixijs-* skill), then check the types in apps/game/node_modules/pixi.js/lib/**/*.d.ts. v7 habits that do not exist anymore: new Application({...}) options (→ await app.init({...})), app.view (→ app.canvas), Loader (→ Assets), beginFill/endFill (→ .rect().fill()), new Text("hi", style) (→ new Text({ text, style })). Skill pixijs-migration-v8.

Layout: logic apart from rendering

File	Role
src/main.ts	the only file that touches Pixi: app.init, Assets.load, sprites, app.ticker.add
src/entity.ts	game state as readonly data + pure functions (moveEntity); Pixi math only (Rectangle)
src/input.ts	keyboard → held keys → direction (KeyboardEvent.code: physical keys, WASD = ZQSD)
src/assets/	images, sounds: import url from "./assets/x.png" (hashed, works under any base path)
tests/*.test.ts	Vitest on the pure functions (import … from "vite-plus/test")

Collisions: walls are drawn with Graphics (rect().fill()) in main.ts; their hit boxes are wall.getBounds().rectangle, passed to moveEntity, which tests hitBox(entity).intersects(wall) one axis at a time (stops flush, slides along). Moving walls: read getBounds() again each frame.

The loop in main.ts, every frame: state = update(state, input, ticker.deltaMS), then copy the state onto the sprites. New gameplay = a new pure function + its test, then one line in the ticker. Speeds are in pixels per second, scaled by ticker.deltaMS (frame-rate independent).

Strictness you will meet

• tsconfig.base.json: strict, noUncheckedIndexedAccess (array[i] is T | undefined), exactOptionalPropertyTypes, verbatimModuleSyntax (import type for types only).
• Lint (root vite.config.ts): pedantic + type-aware. Parameters must be readonly types: readonly T[], { readonly x: number }. Pixi's Application, Rectangle, Sprite, Text, Ticker are allowed as parameters; another Pixi class as a parameter → add it to that allow list with the reason, never disable the rule.
• Imports end in .ts (./entity.ts).
• Top-level await is fine in main.ts (Vite 8 targets browsers that support it).

Checks

The Claude hook runs vp check --fix <file> and the game's unit tests after each edit. Before "done": vp run ready. A visible change: also look at it (vp -C apps/game dev, or a Playwright screenshot, skill e2e).