Solo dev builds 16,500-line browser MMOARPG in a week with $700 of Opus 5.5 tokens
Vickie184 · reddit · 2026-10-02
A solo developer fed 15 years of fantasy worldbuilding lore into Claude Opus 5.5 and, after a week and 36 iterations, produced a browser MMOARPG in a single 16,500-line HTML file.
Highlights:
- 8 classes with full skill trees, starter town, open zones, harbor town, enterable coffee shop, near-endless dungeon
- Fishing, gathering, loot, weather, day/night cycle, old-school slow grind to level 99
- Visible other players, grouping, trading, optional PvP flagging
- Free alpha, no download or account required
The developer says Claude found and fixed most bugs itself, including self-playtesting; he handled creative decisions while the model wrote the code: "The world took me years to dream of and the game took a week."
More from coding & agent
- Dev builds browser 3D game from scratch with Opus 5.5, Blender and Three.js — jason_mayes · 2026-10-03
- Cloudflare Durable Objects now survive client disconnects for long-running agents — threepointone · 2026-10-03
- Dev tired of nbviewer crashing builds serverless browser Jupyter notebook renderer, MIT-licensed — cneuralnetwork · 2026-10-03
- Monitoring Can't Keep Up: What to Auto-Detect When Your AI System Scales — goyalshaliniuk · 2026-10-03
- Security Risks Multiply at Scale: Least Privilege, Isolation, Rate Limits — goyalshaliniuk · 2026-10-03
- 7 Ways AI Systems Fail at Scale: 100 Users Fine, 100,000 Broken — goyalshaliniuk · 2026-10-03