Too random to be fun in this genre.
Very nice graphics and an awesomely fluid engine. However, I was foiled way too many times by a poor fall or the colour at the bottom of the pile coming up over and over again.
I love this kind of physics puzzler and the twist you implement (sleeping) is incredibly enjoyable. I'd love to see it implemented on a game where the puzzles are designed and the order of allowable removals is fixed accordingly. However, in this random format I have to say that it's wholly unenjoyable.