Summary & Key Takeaways ​

• Simon Willison tasked Codex Desktop (GPT-5.6 Sol Ultra) with generating a game from a prompt.
• The AI produced "Moonlight & Mayhem," a more complex and "heisty" game than a previous attempt with Claude Fable 5.
• The initial AI-generated game had a bug (giant raccoon eyeballs) that required a follow-up prompt to fix.
• The article shares the GitHub repository, including textures, prompts, and the full Codex transcript.
• It also provides an estimated API cost for the session.

Our Commentary ​

This is exactly the kind of practical, hands-on AI exploration we crave. Seeing GPT-5.6 Sol Ultra in action, especially with its sub-agents, is genuinely impressive, even with the giant eyeball bug. It really drives home that these tools are powerful co-pilots, not magic wands. The iterative prompting to fix issues is a crucial part of the workflow, and we appreciate Simon sharing the full transcript.