Final Scene was unexpected lol. Pretty cool idea!
Having a box pushing puzzle type game with the added difficulty of needing to be careful of where you move is a cool idea. While also being able to use your other self to move boxes as well.
I think a game like this would really benefit from a more grid like movement system, since there were a lot of times where I could avoid the evil me, but it didn't feel like the intended solution. (Like while falling, pressing space to have the evil one jump over you then) It would also help with some of the weird box physics, since sometimes it would be hard to control boxes well via pushing and placing on to buttons.
Little but on level 2, in which if you're on the button when the box also hits the button, leaving will close the door again. Should check for all buttons in the room instead of just changing door when a button state changes.
I would also find sometimes it easier to just block the evil me (especially on 10) do the level, and then unlock him when I need him. Which may have been the solution, but It made the level a lot easier.
Art is cute, and fitting music to match it.
Nice Job!