Google Play Game
https://play.google.com/store/apps/details?id=com.Shadow.PrjCastle
Martian Assault is a defense shoot em up game where you are to defend against a Martian invasion by shooting down enemy flying space craft. You are the world only hope as you use your gun turret to shoot down Alien Space craft. If you fall the world falls with you.
This Game is under development.  More updates and improvements to come.