loved it, the check points are totally necessary, it will look even better if there was some indication of where why are.
When I die the disappearing platforms are not going back and it's kind of a bummer.
I would also love it if (at least in the first level) you can put an "E" icon above the door (I had to exit the game and come back to remember that I need to press to to move on). Or many better, not a need to press a button at all.