Pretty cool game. I'm not too fond of witches, but I like their pointy hats.
I'm not too good at precision platformers but I beat Super Meat Boy and the first world of Dustforce back in what feels like the middle ages. I think the controls are really good except for the shift key which feels a little awkward for when you need to z - shift - hold z.
I also found a bug where you can get stuck in platforms by shifting from cat to witch in mid air. This is easy to reproduce at the tutorial during the last jump by pressing shift close to the ceiling close to the last gate.
Finally, consider adding a way to restart the entire level. Here are my sick times.
