What they did
A solo developer on r/ClaudeAI built Viper One, a fighter jet game that runs in a web browser on three.js, and says the code came from Claude Opus 5.5 with fal models used for some assets. Claude wrote the cockpit camera model by matching a GoPro fisheye lens to real cockpit footage, a canopy shader with scratches, glare and rain streaks, a multiplayer room server and a ranked ladder. The poster ran several agents at the same time, each on its own git branch for one area (missions, sound fixes, load speed, trailers), and reviewed every branch before merging. They also had the model run long research sessions and physics simulations of real aircraft behaviour, then port that behaviour into code light enough for a browser, and had it profile slow loading and iPhone crashes and fix them.
How it went
The poster says the game went viral on X about two weeks before the post, with around 25,000 players in that time and about 1,000 flying daily, and that the three.js site featured it. Many commenters pushed back on the hyper realistic label, saying the flight felt laggy and nothing like a real jet, while others called it impressive for a browser game. The poster gave no figures on cost or build time.
Worth knowing
The harness was not named, only the model, so the parallel branch setup could have been Claude Code or another tool. The realism claim was widely disputed in the comments, so judge the physics yourself. The branch-per-agent pattern with a human merge review is the part that carries over to other projects.