Constructive criticism: The menu is obviously unpolished, the walls of the levels are kinda ugly and in the beggininng as you don't have a wall behind you, you can wander through space infinitely.
Subjective criticism: The concept was nice, it was fun for a couple of minutes, if you want to go serious with the idea, I suggest adding more mechanics.
PD: After playing this game I became 5 inches taller and I can now breathe underwater. 10/10