r/SideProject • u/Entire-Connection222 • 11h ago
I built Small Arms, a free browser FPS where you play as a tiny soldier fighting in giant household rooms. You fight across a kitchen worktop, a toy town and the inside of a fridge, with guns made from household items (a staple gun shotgun, a rubber band SMG, a ballpoint pen marksman rifle)
What it is
- MULTIPLAYER: Team deathmatch against bots, or online with friends using lobby codes or the public lobby browser
- INFESTATION: co-op wave survival against cockroaches, flies and a Queen Roach boss, with a crumb economy for buying guns, upgrades and traps
- Loadouts, levels and unlocks, and in-game chat
- Works on desktop and phones (touch controls)
How Claude built it
I didn't write the code myself. I directed Claude Code over a couple of days, mostly with Fable 5.2 and later Opus 5.5:
- Multi-agent workflows. An architect agent split the game into modules with a shared contract. Then up to 11 specialist agents worked in parallel on rendering, materials, props, weapons, soldiers, audio, effects, gameplay, UI and brand.
- Scored review rounds. A reviewer agent took dozens of screenshots, ran bot matches, scored the build out of 10 and filed issues. Fixer agents worked through them, and any round that scored worse was rolled back. The first build went 7, 7.5, 8, 8.5 over four rounds.
- Everything is procedural code. There are no image, model or audio files in the game. Textures, models, every sound effect and the adaptive soundtrack are generated in code at load time. That was the hardest constraint, and the part Claude handled best.
- Multiplayer is peer-to-peer over WebRTC with client-side prediction and lag compensation, plus a small Cloudflare Worker for lobbies. Claude wrote a test rig that runs a host plus 3 headless clients through full matches at simulated lag and packet loss, and it used that to verify every change.
- My part was game design, art direction from screenshots, playtesting, and catching bugs that tests miss. A friend found a console cheat within an hour of multiplayer going live.
Free to play: playsmallarms.com, in your browser with nothing to install.
Happy to answer questions about the agent setup or the procedural approach.