Something that has bothered me for a long time: "Extreme%" is actually any%, and "Any%" is actually 100%. How the hell does that make sense? Who came up with those designations, and why has nobody changed them?

To me "any%" means reach the canonical end of the game as quickly as possible (i.e., the final bomb in the list) whereas "extreme%" indicates reaching an alternate ending: the last extreme bomb. Of course that's just a silly justification since extreme% is a subset of any% anyway. Personally I never liked the idea of a category that only partially completes the game (unless exotic bombs didn't exist at some point - in which case the categories would be named after the patches).