Heya, I think this game was - with reference to the theme - actually absolutely innovative!! I'd like to point out a few favourite things in this game to couple with the things I find EH about:
1) As mentioned - very innovative puzzle platformer. You have keys that essentially move away from you, which I think is something that, even if it has been done before, but to elevate it to a core mechanic, which in my opinion, can see a lot of potential and can be amazing once you flesh out the game with much more mechanics.
2) Very good tutorial-less approach. Your lack of tutorial, and the way of teaching a player without even using text is something to be commended about. It is so seamlessly integrated that the player just learned what needs to be done with no words exchanged. Perfection!
Some things I find EH:
1) The controls definitely need some more work on. It goes without saying that the controls are a bit iffy, the jumping feels very, very floaty and you could tweak it to feel better to control overall. The initial jump feels like an acceleration is applied - rather than instantaneous force and that makes it feel weird. If the initial jump started with a burst of speed, before decelerating - instead of an accelerating motion - I think it would feel better!
2) I think the game would work better if it wasn't a 2d side-scrolling puzzle platformer, but rather as a top-down puzzle platformer. It would give more emphasis on the puzzle aspects of the game and throw away the unnecessary platformer parts that don't contribute much to the overall gameplay. Just my 2 cents.
I quite enjoy this honestly. Kudos!