I completed the game.
I like the wall textures and the overall dev art. If you made the music yourself then it's fine and appropriate too. The field of view feels right, instant movement feels good, the game controls perfectly and the core mechanics is a cool and original concept which could probably easily scale to some larger, unique game with variations of how what's in the sky works between levels.
I won't say enemies which can't affect you in any way is no big deal but the other parts of the game work.
Thanks for sharing.