Zombies have attacked and mankind has been devastated. Every day is a battle in the war to survive. Few remain to hold them off. Shoot those zombies and save the world.
Shoot enemies down and advance to the next level. As the game progresses more weapons become available and you will encounter more challenging enemies.
When your balloon crash-lands in a wasteland of fowl creatures, its time to survive. Upgrade your weapons, fort, and turrets while you try to fix your balloon.