Kirby's Adventure is a colorful game that's very long for a NES title. However, a bug was discovered which caused unpredictable results upon using the Stone power while entering water from the side, instead of above as intended. Using the Mix ability and a subpixel-perfect slope clip, this scene-corrupting memory glitch can be done in the very first level.
This movie by DarkRiolu27 uses the glitch to advance the game to the credits, doing so 105 frames faster than its predecessor.
This is thanks to mixing later, leading to greater speed preservation and lag reduction.