Sonic 3/Sonic & Knuckles Disassembly

About

Sonic the Hedgehog 3 (1994) and its follow-up Sonic & Knuckles (1994) are Sega Genesis platform games in which players guide Sonic, Tails, and later Knuckles the Echidna through side-scrolling levels to stop Doctor Robotnik from relaunching his Death Egg space station. This is a full disassembly of Sonic 3 and Sonic & Knuckles, organized by function — general assets, per-zone level data, sound, and lock-on-specific data — rather than by raw data type. It can build byte-perfect copies of the standalone Sonic 3 ROM, the Sonic & Knuckles ROM, or a combined Sonic 3 & Knuckles ROM via a build flag, and includes verification scripts to confirm the output matches the original ROMs exactly.

Getting started

Build using the included Windows batch files or the cross-platform Lua scripts (requires Lua 5.3+) to produce byte-perfect ROMs. Project files for the SonLVL and SonED2 level editors are included for those who want to modify the game.

Additional notes

Audience

The README warns that modifying Sonic 3 & Knuckles directly requires ASM knowledge, and recommends the more accessible Sonic 1 or Sonic 2 disassemblies as a starting point for beginners.