Sonic 3 and Knuckles: The Challenges - Tag Team 2
Video of me S-Ranking ColinC10's hack of Sonic 3&K, Sonic 3 and Knuckles: The Challenges. I know, it ain't a goddamn difficult level, but I suck, ok? In case you somehow got to this video without actually playing the hack, the levels are all the same, but with different gameplay twists for each level. This particular one is Tag Team, where you have to alternate between Sonic and Knuckles to complete the level as fast as possible.
This level is very Knuckles heavy, I only needed Sonic to get up past the last swing, and for the boss to speed things up.