I like it a lot. I like how you can choose any level, and it still keeps track of each completed level. I enjoyed how it starts off easy so you can get the hang of it, then gets increasingly harder. The music is great, I like how the beat makes you want to keep going.
A good challenge - however the "level completed" noise hurt my ears, alas when I turn my volume down I can't hear the music. Nonetheless, good game.
Quite a fine puzzle, fun and simple.
Simple, challenging and addictive. Well executed.