This game has some impressive accomplishments of tech. We have build it with JSB (Javascript Binding) that means, we wrote it with Cocos2D-HTML5 (you can play the game at http://last.nakedmonkey.com.br) and have attach together with several UNIQUE libs for Android.
You can play it and try out the Google Play Services, we have around 30 achievements and 2 exclusive leaderboards! Just login with your Google Account and submit your scores to the net!
We have also used the Soomla projet to create IAP for our game, using it from the JSB. I am preparing an example of how to do it to upload into the GitHub, but did not had the time yet, sorry guys!