Simon Willison ships vibe-coded RTS in 321 agent commits

After 12 major iterations and 321 commits by coding agents, Simon Willison has released Battle Drones, a Command & Conquer style real-time strategy game that supports multiplayer between two devices sitting within microphone distance of each other.

Willison writes on his blog that this one, unlike his previous vibe-coded experiments, is "actually fun to play." He credits one instruction. "I still can't get over how well the prompt 'Make it a LOT more fun' worked," he writes. He says the commits were "mainly Claude Code," and attributes to that single prompt the features that followed: strategic openers like Blitz, Industry and Air Wing; call-down powers Barrage, EMP, Drop Pod and Sky Hammer; adaptive music; a Last Stand survival mode; and AI testing across 1,200+ simulated matches.

The novel part is the local multiplayer. "The multiplayer-over-audio thing is a first for an RTS as far as I can tell," he writes. An online mode followed, running on a Fly.io WebSocket relay that, he says, "should cost me no more than $2.19/month." He started the project in July on an earlier Claude model and later moved to Claude Opus 5.5 for the harder work.

Willison does not oversell the result. "I wouldn't personally dream of submitting Battle Drones to an event like Steam Next Fest," he writes, calling it "still way too low effort to warrant consideration as a legitimate indie gaming project." Two of the AI practitioners we track in our Who's Who directory shared the link the same day.