game-conceptlisted

# Game Concept Reply in the project conversation language (CLAUDE.md → Language); code, identifiers, paths and commit messages stay in English. Template `.claude/docs/templates/game-concept.md`. Reference `threejs-webgames.md`. ## Phase 1: Pitch and loop Questions: genre, the player's "verb", session (minutes), platform (mobile web first?), single/multiplayer, references. Three core-loop variants with "why it is fun to repeat". ## Phase 2: Mechanics, progression, content Rules with parameters (mark: in data); a difficulty-curve table; MVP volume vs full version. ## Phase 3: Feasibility Engine with justification (3D → three.js r185 WebGPU/WebGL2; 2D → PixiJS 8/Phaser); budget: 16.6 ms frame, draw calls, memory, first load on 4G; networking (multiplayer → server-authoritative on Go, tick rate); saves; **spikes** to test risks (e.g. "1000 instances on a mid-range phone"). `threejs-engineer`/`web-game-engineer` via Task — risk assessment for their part (in parallel). ## Phase 4: Accessibility, metrics, prototype Accessibility settings; retention metrics; prototype plan: what playability validates first, timeline, the "fun" criterion — measurable (sessions, minutes, a question to N testers), so `gate` can record a result, not an opinion. ## Phase 4b: `gate` — the prototype go/no-go `/game-concept gate` (after the first playable slice, before backend/multiplayer investment): read §11 of `docs/specs/game-concept.md`, ask for the measured result against the "fun" criterion (pl