I did start this a few months ago, and got to the end of World 4 (of 10). I don’t recall why I stopped playing as it isn’t a bad game. Probably something else caught my eye.
Since I’m in the mood for mopping up started-but-unfinished games at the moment, I continued with it and after a couple of hours had smashed my way through to the end of the game. It was pretty good fun, but frustrating in that, as a Breakout type game, you’d expect more control over the rebound angle of the ball (or rather, Kirby) with the bat. You get very little, and it sometimes seems a bit random. Also, everything is a bit big for the small playfield, so some levels are very cramped (and difficult as a result).
Anyway, it’s still worth playing.