Kruela Mario is a glitch-puzzle-kaizo hack containing 26 levels with 29 exits. Savestates and slowdown are highly recommended, Lua can also be useful for glitches that depend on sprite slots.
This hack requires you to use a lot of glitches.
Also, as a gimmick, I decided to make the entire hack in Esperanto - Use a translator if you really want to understand the message boxes. Note that I don't really speak Esperanto, so correct me if you find any grammar mistakes...
I like the idea behind this hack and there are a lot of creative gimmicks in it, but a lot of the levels have a hard time deciding whether or not they should be platformery or puzzly, and they end up being kind of empty as a result. Also the last level is kind of anticlimactic despite being long.