This hilarious video has been around youtube (posted by several people) for several years, and it's just as funny each time I see it. I thought that it would be neat if the levels were added to Crossover as an extreme set of levels. Mario might be the only character to be able to accomplish it, but I feel it would be an awesome addition to the game. From what I can tell, it's a ROM hack of Mario 1 called Super Mario Bros Forever. I feel as though this (or custom levels similar to this) would be a fantastic addition to the game for the more hardcore players among us.