ZiGGURAT is a shooter game developed by Action Button Entertainment and released on iOS.
The end of a much longer story -- a story which ends with The Last Human On Earth standing atop a stratosphere wielding a laser rifle against an endless wave of relentless alien freaks. Where did the alien freaks come from? How did our hero get to the top of this pyramid? We have no time to think about such things: there is only time to shoot. The situation is hopeless: this is the end. Your only goal is to enjoy taking out as many of those alien freaks as you can.
