Super Mario Bros. 2 is the infamous sequel to Super Mario Bros. that was released only in Japan for the Famicom Disk System. Considered too difficult and too similar to the original game, it was skipped over for localization in favor of making Doki Doki Panic into the actual Super Mario Bros. 2 for the NES. This game would later be remade in Super Mario All-Stars as Super Mario Bros: The Lost Levels.

The efforts of many authors were combined to find a way to beat the game just a little bit faster. By exploiting a subroutine bug in the final level of the game, arbitrary code can be executed that can make it skip right to the "Congratulations" sequence. For further details on how all six authors got to that point and what they each contributed to make this run, you can read the authors' notes.