A Head-to-Head Comparison of AI Coding — Round Two Introduction A while back I pitted Opus 4.5 against Kimi 2.5 in a 3D maze runner build-off. This is the rematch. I had hoped to run this round with Fable, but I was a day too late — so Opus 4.8 took the seat instead. The harnesses were native to each model: Codex for GPT-5.5 and Claude Code for Opus 4.8. Same challenge as before: build a complete 3D maze runner from scratch. Opus 4.8 (Claude Code) 00:30 — Claude Code opens by asking me questions about the framework and algorithm to use. 05:20 — Thinking done. It leaves plan mode and starts writing code. 08:51 — Build succeeds; installing Chromium. 09:53 — Running through the maze, it detects graphical issues. 11:04 — Graphical issues appear fixed; it moves on to check for graffiti on the walls. 12:31 — It decides the graffiti should “desaturate in dim corridors,” so it makes them glow more. 14:01 — Running final tests and cleanup; one last production build. 14:42 ...