Interesting mechanism with the key. I liked the puzzle part.. The level design could be improve, it's hard and too fast, you should begin very simple and increase difficulty step by step. Using air control to avoid and go on the platform on top of you is not an easy jump or jumping and use "down" key to get the key in the air (would be easier if you just have to touch the key to collect it), also the pike hitbox is smaller than the visuel. I've reach the first bonus level and surrend there.