Really, really good. Took me some minutes until I could stop playing :D!
Just some minor suggestions for you:
- The score seems to depend on the stones you get. Big stone at the beginning => higher score. This just pushes the score limitation more in the direction of luck. Would it be boring to use the same stones all the time? I know, in that case you must do the same thing every time but the it is not that much about luck.
- I clicked a stone when I saw another one which fits better. The clicked stone then fell down and I lost. Is that planned?