The concept is basic but it's very addictive.
Graphics = Simple and clean 9/10
Music = Good but only one track that doesn't repeat itself. 7.5/10
Learning Curve = Very easy to learn 10/10
Game play = Easy but your fingers may get stuck on the screen or not get detected for the cold or whatever - so that's a down side. 9/10
For a dollar, this game is worth it's money and is perfect to kill a few minutes when you're waiting for something. Though I bet you'll probably find yourself playing it more than you should!