Ingame purchases unfortunately only PlayStore // [Edit] now through Amazon

One thing first: The graphical presentation is truly beautiful. The colorful neon colors harmonize beautifully and the sound effects are nice. Never affects the game overcharged. Class!

The game is also a lot of fun and is without the ingame purchases very fordernt. Nevertheless, I have done it without the extra weapons to achieve it each 3 stars in the first 4 levels. After that, it is however difficult to sack and upgrades are increasingly becoming a basic requirement Platt close to all the aliens. The pity is that I can not handle well on the Amazon App Store this ingame purchases. The money I would like to invest.
A credit card I did not, so I have to wait until there is another alternative.

[Edit] now on Amazon. CLASS !! 5 Stars