This was nice, I won pretty easily and I'm glad I beat this cube :D
The game is a bit empty, and it would not be a problem if it was only visually, but even the gameplay feels too simple to be really enjoyable. More screenshake, small combos by pressing two keys, playing 1 cube against 5 or 6 to feel really strong, etc. a few simple and basic things that could have make the game way better :)
Also, you should consider making it a local versus game!