I recommend approaching this as something in between a puzzle and a rhtyhm game. Each level has a certain "flow" that can be followed in order to easily get three stars. Figuring out this "flow" is the challenge. You can pass levels by just trial and error but the levels that just click are the best. The later levels do become harder, but this is mostly due to unnecessary padding. Like adding obstacles like mist, while reusing old levels. This just feels unnecessary. Played almost all regular levels, except the last one. The last one just felt unfair.

So, it's a cute little puzzle game that's definitely worth picking up on sale.