In this 11-minute video, a series of cunningly engineered custom Mario levels are used as a rhythm section to accompany a spliced-together medley of chirpy anime soundtracks. The maker (IsoTkhs on YouTube) has set up the levels so that various bumpers and objects keep Mario moving, jumping, flying and bouncing over in-game objects at very precise timing, so that each object's bounce-noise forms part of the percussion for the tracks. The clip goes on and on, which is like the Mario percussion version of Chico Marx looking casually away from his piano, cracking jokes, moving around, while one or both of his hands effortlessly continue to plunk out some insanely complex and witty bit of ivory-tickling. Clearly the maker is saying, "I can do this all day long. You thought that was cool? Check this out. And this. And this. And this. Oh, pick your jaw up, there's still more to come. Yeah, this too. Ha, yeah, that one was pretty good. Now, watch this."
If you only watch one 11-minute YouTube of anime music accompanied by custom Mario levels today, make it this one.