Nice game !
I found the music appropriated, could the enemies be in sync with it ? At least with a subdivision of the BPM ? that would help to figure how they gonna move while the cube is moving.
I also found that difficulty does not increase in a smooth way, some time it passes from hard as fuck to super easy or the opposite, it doesn't give a nice feeling of progression.
Also, a death counter would be nice.
but very nice game indeed, continue like this !