There's an ads, but that's pretty common on free apps. What kinda of irked me was that it's actually not a full game after all. There's only 11 levels to play, after that you have to make an in-app purchase to unlock higher levels. The price isn't expensive, but I kinda feel cheated. Oh, well, it's fun while it lasts...
Except that, it's really is fun! I like the game style, and the graphic is nice, and the music is pleasant as well.
Would certainly recommend it for casual gamers!