You made this in a day?! I never would have thought of something like this, the only things that I could say that needs to be improved on are that they were no clear indication that you could double jump, and that on the last level, it was hard to see the unreal world, which led to a couple of unfair deaths. This is still really impressive that you made this in a day, and it's good that you're starting game dev at the age you are now, I can imagine you making a game like Celeste in a couple of years time!