I've only played the first couple of puzzles, but so far it's quite fun. Getting the ball to bounce and split everywhere it needs to within the limited play area is an interesting challenge.

One piece of advice: You only get one target you can place, but you can trigger additional pixels by 'grazing' a triggered pixel. (i.e., hitting a space adjacent to an already-triggered pixel. You don't even have to hit it head-on.) This could probably be better communicated by the tutorial on level 2, where it first becomes relevant.