Moonlight & Mayhem (Raccoon Heist by Codex + GPT-5.6 Sol Ultra)

Simon Willison’s Weblog · 2 months ago · 11 ● 2 sources

A developer used Codex Desktop with GPT-5.6 Sol Ultra to generate a working browser-based raccoon heist game from a single prompt, producing a more complex version than Claude Fable 5 had created from the same premise. The GPT-5.6 Sol version took 52 minutes and featured raccoons stacking in a museum to steal a golden sardine, though it initially contained a bug with oversized eyeball spheres that required two follow-up prompts to fix. The developer published the full game, textures, and development transcript on GitHub, demonstrating how modern coding agents can build functional games from natural language descriptions despite occasional visual errors.