A top-down action roguelite — no build step, no framework, no external assets. Just a canvas, a game loop, and a lot of procedural variance.

Almost entirely generated in one shot from spec.md using Qwen3.6-35B-A3B (~2 bit). on Nvidia RTX 4080 with 16GB VRAM in about ~20min.

• Procedural worlds — 120×90 tile maps generated with cellular automata smoothing on value noise. Every run is different.
• Equipment system — swap swords and shields. Ground items compare stats on hover, click to swap. You always have both slots filled.
• Enemy traits — randomized speed, damage, HP, aggression radius, leap-attack chance, and shield reaction. Visual hints (shape, color) emerge from the trait roll.
• Shield mechanics — raise with right-click, drain stamina, break at zero with cooldown. On-block effects (slow, paralyze, reflect) proc randomly.
• Combat feel — hitstun, pushback, knockback, crit feedback, lifesteal particles, lerp camera, DPR-aware canvas rendering.
• Cozy aesthetic — warm muted palette, rounded silhouettes, breathing idle bob, procedural tile variation, soft reticle. No blood.

./run.sh --port 8000        # idempotent: creates .venv, installs deps, starts server

Then open http://127.0.0.1:8000/. The game drops straight into a fresh world — no menu, no loading screen.

• Python 3.11+
• uv (for venv + pip)

uv venv .venv
uv pip install -r requirements.txt --python .venv/bin/python
uv run src/server.py --port 8000

Mouse cursor is hidden over the canvas; a soft circular reticle is drawn instead.

FastAPI serves static/ at http://127.0.0.1:8000/static/. The browser loads ES modules directly — no bundler.

src/server.py          — FastAPI app; serves index.html at /, static/ at /static/
static/index.html      — single <canvas> + one ESM script entry point
static/js/main.js      — game loop (fixed 60 FPS accumulator), shared `game` state
static/js/world.js     — cellular automata generation, tile helpers
static/js/player.js    — movement, combat, shield, dash
static/js/enemies.js   — trait-based AI, spawning, drop table
static/js/items.js     — affix generation, ground pickups, swap UI
static/js/render.js    — camera, tile/enemy/player/item rendering
static/js/ui.js        — HUD (hearts, stamina, kills, equipped items, tooltips)

main.js owns the single game state object. All modules receive references — no globals.

• window.game exposes full game state in the browser console.
• No error boundaries — a JS error crashes the game loop. Check the console.
• All rendering goes through render.js. If something isn't visible, check camera position and canvas dimensions.

See AGENTS.md for a living list of gotchas (dead code, duplicate functions, hardcoded constants).

If you find this interesting, consider buying me a coffee.

See LICENSE file.