Quite good
The presentation (music, art style, animation) are all so cheesily cheerful and inviting that I actually like it for its camp-value. Still, the visuals and sound are ultimately uninspiring and forgettable.
The gameplay is solid. It's not nearly the best of its kind, but it's well executed. One thing I appreciate is that getting the most powerful blast is actually really, really hard. The way in which you unlock new balls is well-designed, which it makes the game more rewarding to play. You earn an extra star from me just for that.
The one thing I'm really annoyed by is that you can't have more than one item. I was saving my boost one time, when I hit another item bubble, thus replacing the item I was saving with a different one. What's even worse is that it was a pack of stars, not a boost. So even if I could only have one boost, it doesn't make sense that getting stars would throw my boost away.
Nothing special, but well done.