I really liked this game! Every part of it. Didn't think it to be too difficult, the speed changes depending on mouse distance are awesome, maneuvers are smooth to be done and it has an overall chill experience. It's the "simplicity" of it that makes it great!
I agree with some comments on the UI. Replacing the keys with gems icons should be better and maybe only adding them to the UI after collected, because at one moment I thought I had all the keys, but one was still missing in between the other icons. Also known as, I'm blind! lol
Excellent work! Keep it up!