Extremely unique and a great innovation on a classic. The difficulty wasn't too bad, one or two playthroughs got you used to it fast.
As you got more cubes, it seemed easier to just keep the cubes in the air and getting random hits instead of actually aiming, which was already difficult. I guess I mean that it gets harder then easier then harder again, which is an odd feeling.
Very, very good. A lot can be built on this, I'm glad you submitted it. 5 and 10.