I let Opus 5.5 run for 54 hours straight and it built a full Minecraft boss mod ($2,032 of API usage) Part 1 of 4

I'm a vibe coder. I don't write code. I gave Claude Code (Opus 5.5) an idea for a Minecraft mod: a new dimension split into four layers, each ending in a boss. Then I let it go. It ran for 54 hours, and its longest stretch without a break was about 35 hours, including overnight while I slept. It wrote the design doc, then the code, the models, the animations and the boss AI. It also built its own test harness: a hidden game client that plays the mod, takes screenshots and checks its own work. Most of the heavy lifting went to subagents (48 of them), with the main session reviewing their work. For audio, the 19 voice lines are ElevenLabs v4 (released the day it needed them) plus 8 ElevenLabs sound effects, and Claude checked every take by transcribing it back. The other \~350 sounds it synthesized itself, with code. **The numbers** * 54 hours start to finish (Sep 27 to Sep 29) * About 12,000 API calls * $2,032 of usage at API prices (I'm on the Max plan, so that's what it would…