# Sonic CD (Mega-CD): Little Planet: Sonic CD recompiled from a matching disassembly

> Source: <https://reversedwithai.com/p/sonic-cd-mega-cd-1ee8d044>
> Published: 2026-10-23 06:46:11+00:00

## Evidence at a glance

Based on the linked sources. The author's reported result and independent confirmation are separate checks.

- AI involvement
- Reported models: Claude. Tools: SDL3, FFmpeg, Python 3. The writeup below describes the work attributed to AI.
- Reported result
- Works. This is the directory's source-based outcome classification.
- Independent confirmation
- Not reported.
- Human work and limitations
- The project uses a static recompiler to turn 68000 assembly into C. The commit logs explicitly credit AI models as co-authors for specific implementation tasks, such as audio driver handling and widescreen menu adjustments.

### Original sources

## What was done

Little Planet is a Sonic CD port built from a byte-identical disassembly and static recompiler. It features True16:9 widescreen, a remastered opening, and high-level HLE implementation of Mega-CD hardware, requiring a user-provided disc image.

Little Planet is a Sonic CD recompilation project that provides a disassembly of the game's code, which reassembles byte-identical to the original disc. A static recompiler translates this code into C, which is then executed and verified frame-by-frame against an interpreter. The project implements the Mega-CD hardware, including the 68000 CPUs, Z80, VDP, and audio chips, using a high-level implementation (HLE) to replace the original BIOS. The README documents that the Japanese release (G-6021, SHA-1 5b0ac16233028bcd8691c71b0a749b8d485dae7c) is the primary tested version, while others may boot but remain untested. Development commits in the project repository include the strings 'Co-Authored-By: Claude Opus 5.5 [\[email protected\]](https://reversedwithai.com/cdn-cgi/l/email-protection#6f01001d0a1f03162f0e011b071d001f060c410c0002)' and 'Co-Authored-By: Claude Sonnet 5.5 [\[email protected\]](https://reversedwithai.com/cdn-cgi/l/email-protection#4c22233e293c20350c2d2238243e233c252f622f2321)' in their metadata. The port supports True16:9 widescreen, a 4K 60 fps remastered opening, and various CRT filters. Users must provide their own disc image, as no game data is included. The project is available at [https://raw.githubusercontent.com/carlosrmz009/littleplanet/HEAD/README.md](https://raw.githubusercontent.com/carlosrmz009/littleplanet/HEAD/README.md).

## Reproduce it

```
Build the project using the provided scripts (build_linux.sh, build_mac.sh, or build.bat) and run the resulting binary with a path to a valid Sonic CD disc image (e.g., ./build/littleplanet path/to/sonic.cue).
```