Greedy money-grubbing makes this (otherwise good) game unenjoyable, even despicable. $6.99 for TWO HOURS of unlimited "energy," which is the currency needed to be able to play. Unreal! What other game charges you that amount to play for two hours!?! Otherwise, you have 60 energy units which get used up within a few rounds. Developers, shame on you. Be respectable like everyone else and charge a couple of bucks for permanent unlimited energy.