I agree with the comment about looping the music. Also, it was a bit loud compared to the sound effects (but not a big deal). The tutorial text looked nice and clean.

I really liked the way the game eased you into learning it's controls, plus the atmosphere, despite just being cubes, worked really well thanks to the music! A simple game design idea that was executed well. I'd say this is pretty good! 

I don't think I've ever played a 3d game with controls that feel as good as this one. The way everything in this game works together all feels very smooth.

I would appreciate a restart button, I think I've trapped myself twice. Being able to rotate the y perspective would be useful. Also, please loop the amazing music.