For something that only manipulates the music, this is pretty fun. Inverted JRB/DDD and inverted Bowser stages are by far my favorite compositions from this mod, and inverted Metal Cap is just chaos, lmao.
What surprised me is Lakitu's introduction and Key Get jingles are just Mario chanting, as well as Endless Stairs and Final Bowser being unchanged for some reason.
EDIT: Ran into Mips with glitched animations while this mod was off, so it can't have been the cause for that.
