Tree Appreciator
Simon Willison used Claude Opus 5.5 to generate a Three.js spot-the-difference tree game.
Simon Willison prompted Claude Opus 5.5 Max in the default Claude iPhone chat app to build a Three.js game called Tree Appreciator. The game shows two algorithmically generated trees and asks players to appreciate their differences, with music, animation, and achievements. He said Claude worked for about three hours and seven minutes before returning the game.
- Built in the default Claude iPhone chat app, not Claude Code.
- Prompt asked for a fun, beautiful spot-the-difference tree game.
- Claude ran about three hours and seven minutes before returning it.
Tool: Tree Appreciator Another game experiment with Claude. This one used the default Claude iPhone app (chat mode, not Claude Code mode), where I prompted Claude Opus 5.5 Max with: Build a three js game called "Tree appreciator" - it shows you two algorithmically generated trees and the game mechanics is about appreciating the differences between them. Think hard about how to make sure it is both fun and beautiful. Somewhat embarrassingly given my recent talk , I've found that telling Opus 5.5 "make sure it is fun" works uncomfortably well. In this case Claude crunched for 3 hours and 7 minutes before retuning a cosy little spot-the-difference game with music and animation and achievements…
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