Case study
Snowboard Kids 2: an LLM-assisted N64 matching decompilation
A public matching decompilation of the N64 game Snowboard Kids 2, begun in 2024 with community decompilation tools. The author’s dated posts document Claude, Codex and GLM workflows, including headless one-shot loops, similarity-based function scheduling and hook-guarded, hash-checked builds, through a reported complete function match.
- Targets
- Game
- Category
- Independent reconstruction cases
- Relationship
- Independent reconstruction project
- Sources reviewed
Requirements & limits
- Prerequisites: Building needs the user’s own big-endian Snowboard Kids 2 ROM, make, Python 3, MIPS binutils and the toolchain installed by make setup; the README reports testing only on x86 Debian/Ubuntu and macOS. It states the repository has no game assets or assembly, although the reviewed tree tracks menu-sprite PNG and palette files under assets/.
- Testing evidence: Progress figures are author-reported. The 2026-02-16 post describes matched code rising from about 25% to 58% with one-shot loops, then to about 75%, with 124 functions left; the 2026-05-17 post reports every function matched. The 2025-11-27 post’s 79% figure was a projection.
- Limits: Byte-matching C is not documented or idiomatic source. The 2026-05-17 post notes remaining __asm__ coercions, many generated names and structures still needing cleanup, and graphics/audio assets mostly handled as binary blobs; the 2026-02-16 post describes brittle agent matches.
- Attribution: Agent assistance is not quantified beyond the posts. The 2026-05-17 post dates the first commit to September 2024 and credits four named N64 decomp community members with significant contributions, especially across the final ten functions; the 2025-11-04 post describes a human-led loop. The work relies on community tools such as splat, m2c, decomp.me, asm-differ and decomp-permuter.
- License: No license file is present at the reviewed commit. The June 2026 Snowboard Kids 2: Recompiled release and the August 2026 decompilation of the original Snowboard Kids are separate projects.
About this entry
The description was reviewed against primary sources.
Primary sources
- README.md GitHub · cdlewis/snowboardkids2-decomp · Revision 352a26f
- https://blog.chrislewis.au/using-coding-agents-to-decompile-nintendo-64-games/
- https://blog.chrislewis.au/the-unexpected-effectiveness-of-one-shot-decompilation-with-claude/
- https://blog.chrislewis.au/the-long-tail-of-llm-assisted-decompilation/
- https://blog.chrislewis.au/snowboard-kids-2-is-100-decompiled/
- assets/sprite_sheets/menuUiSprites GitHub · cdlewis/snowboardkids2-decomp · Revision 352a26f
More in Games
- Snowboard Kids: an agent-assisted N64 matching decompilation · Case study
- Sonic Advance 1 & 2: a matching GBA decompilation with widescreen ports · Case study
- Sonic Advance 3: an AI-assisted match of one enemy module · Case study
- Star Fox 64: a complete matching Nintendo 64 decompilation · Case study
- Super Mario 64 DS: matching decompilation with relocation checks · Case study
- Super Mario 64: ROM reconstruction with explicit comparison gates · Case study