Hacker News AI · 10/6/2026, 1:09:27 PM
Opus 5.5 Autonomously Clones SimCity 2000 via Subagents and Decompilation
A developer used Opus 5.5 to autonomously clone SimCity 2000 into a WebGL low-poly version within days using a single prompt. The model leveraged Ghidra for decompiling original PowerPC code, deployed 27 subagents for parallel execution, and built a Python verification harness running 10,000 game days to ensure identical state logic. This case demonstrates the practical capability of frontier LLMs in complex reverse engineering, multi-agent collaboration, and self-verification loops.
SOURCE COVERAGEOriginal coverage
Music by Kevin MacLeod (incompetech.com), licensed under CC BY 4.0 · An independent fan project, not affiliated with Electronic Arts or Maxis · · dator.dev
作者发帖说明（HN）：
This is a clone of simcity 2000 I (using Opus 5.5) built over a few days. It started with a single prompt "create a typescript webgl low-poly version (full replica of game logic) of simcity 2000. the original is available here for inspection [...].zip".
It then decompiled it using Ghidra and started translating the old native PowerPC code function-by-function. After about 2 hours, using 27 subagents, i had a running version in my browser. After a follow up prompt (make sure all aspects of the game is implemented correctly and accurately), Opus decided to use a PowerPC emulator (Unicorn) and write a harness with faked Mac system calls in Python for verification, running 10,000 game days generating an identical game state. After that it has basically just been polishing, and adding a few subtle modernizations like, smog, depth-of-field and environmental sounds to make it a bit more immersive without killing the original nostalgic vibe.
All 3D and vector assets are generated with code by Opus, and the bitmap image assets are generated by GPT Image 2. The music and sounds are not genai because all AI audio models i've tried sound terrible, so the music and sounds are CC-licensed. The music is from Kevin MacLeod, https://incompetech.com/
I created this because I wanted it and to see how capable Opus 5.5 was. It turned out much better than expected, so I figured I'd share it.