It's a neat idea and an interesting combination of a few different games (thinking Nubby's Number Factory, Pinball, and Ball X Pit).
I found myself wanting things to escalate more as I played. The shapes seem to move at the same consistently slow pace and there's no penalty for them reaching the top of the screen as far as I can tell so it feels like something that would add pressure or challenge to the player would help keep the interest and intensity up the longer you survive.