How a developer decompiled N64's Snowboard Kids in 84 days

Reverse-engineering a Nintendo 64 game into clean C code used to take years. A team just finished Snowboard Kids in 84 days.

Developer Chris Lewis announced that the 1997 N64 title Snowboard Kids is now 100% decompiled. Every one of its 2,145 functions now has matching C code that compiles into the exact byte-for-byte machine code of the original cartridge. The project took one-seventh the time of its sequel, Snowboard Kids 2, thanks to prior experience, community help, and AI agents automating low-hanging library code.

Why it matters: Speedrunners get access to exact formulas for CPU pathing and player speed logic. Beyond data-mining, clean source code gives modders the blueprint needed for native PC ports and static recompilation.

Decompiling wasn't just about reading assembly; it meant wrestling with SGI’s proprietary IDO 5.3 compiler. Because IDO shifts code aggressively across optimization passes, small C tweaks often broke the output completely, requiring human experts to step in on roughly 4.8% of matching commits.

AI can churn through standard Nintendo SDK code, but matching closed-source 90s compiler quirks still takes human intuition.