It's an fun short little casual game that can easily be beaten in one sitting. If you go for the medals it makes it a bit challenging and fun for people that otherwise wouldn't enjoy a game like this.
The music is quite good and non-annoying. A lot of games have background music that is very noticeable and loud, but this is perfect.
The things I didn't like are fairly small. It was a bit annoying that if you wanted to reset the level you had to go back to the menu and select the level again. Pressing 'R' to restart would make messing up a lot less frustrating.
Level 8 is a lot more difficult than any of the other levels. I feel it should be level 10. All of the other levels are really easy to get the par on in comparison to it. I think the game would actually be quite a bit better if level 8 was removed entirely. The other levels are of a fairly consistent difficulty but it's a lot more difficult than them, it feels out of place.