Attack on Titan is a Japanese manga series written by Hajime Isayama. It has become a big success, with over 28 million volumes in circulation as of 2013. (via Wikipedia)
The game of DeNA is one of them. The game is based on the world setting and image of comics. Players become a deportee from the community, build one's village in the wasteland and the wall, and prevent the attack of titan.
They accept the pre-registration in teaser site.