The difficulty ramps up way too fast, and the floating is hard to understand for the player. It would be best to add some sort of bar to see how long you've got left, and maybe some particle effects.
The music is good, but it would have been best to not restart it every time you die and just let it play, it gets really annoying if you die in quick succession.
The concept of loop seems to be an afterthought, as you just restart seemingly without any changes.
Good job !