Pong game recompiles its own source code every frame — winning entry at IOCCC29 was generated by a custom compiler

Pong game that recompiles itself every frame wins the IOCCC29 obfuscated C contest.

Jonah Uellenberg won the Ping Pong Prize at the 29th International Obfuscated C Code Contest earlier this month, with a version of Pong that recompiles its own source code on every frame. Each run of the program prints the C source for the next frame, with the current display and game state embedded inside it, so compiling and running that output advances the game by a single step. Somewhat ironically, Uellenberg didn’t write the obfuscated code himself; instead writing clean, commented source in a programming language he built called Insert, whose compiler generated the scrambled C that took the award.

Today in cursed code: a computer program that plays pong by modifying its own source code. (Each frame is a new compilation). https://t.co/kS2ACZ7r79 pic.twitter.com/7yIc9tXSdPJune 26, 2026