The art is great the music it’s matching the atmosphere of the game, nice work.
But it’s very hard to bounce and move at the same time, it needs a very precise timing. and some time the platforms doesn’t help, and you fall a lot, and take a long time to get back.
Other thing it’s the cristals, since you are jumping all the time it’s hard to get them all, maybe some kind of magnet to pull the itens towards you will help with that.
I’ve made a review of your game on my youtube channel.