I don't see how anyone would want to pay 15$ for quite simple game...
There are lots of great and FREE games on Kong. I would hate to find out that for example next Gemcraft could be a shareware... :(
I've completed the game and I must say that is the most boring, pointless and tedious game ever on Kong. Bloody hours of clicking the attack button!
If it were not for the badges I wouldn't play even for 15 minutes!