I gave it 2 stars because I do enjoy the game. Problem is that it is buggy. I purchased 2000 credits. After a crash, it double and later lost all credit. So without unlocking, I lost 2000 credits. I am owed credits or real coins. I would not recommend, purchasing credits until then. It seems to be an on going problem from what Ive read in the support forums.
Will upgrade ratings when these problems are solved.
JW Mac about HexDefense