I really love the idea and the style. The jump physics are a bit off in my opinion (I'm very picky with those), I would add some interpolations specially in-air. Something this game would benefit a lot is a progress bar or some number indicating the height you're at. It can easily be faked by adding a <1s timer that stops when player is_on_floor and starts when not (if it isn't active), and then when timeout() add height += 1. Simple but gets the job done.
Anyway, love the game, congrats!