The game is really great. It is completely without the use of real money to play, if you naturally have patience. If the tank is used up, you have to either wait a few minutes and you fill it up with diamonds, which are found in small numbers in the game or have to buy with real money. Compared to other parts of trials are completed various missions here. This is in my opinion very motivating and boredom not only on. The graphical presentation is brilliant. The game also runs smooth as silk on the Kindle Fire HD. So what can I say, try it yourself, you will have lots of fun with it.