Blow apart big waves of zombies using an array of guns and hired buddies to fight by your side. Purchase bigger and better guns and hire assistance with big firepower to give those hoards of zombies a good spanking, keeping them away of your territory.
A war has started and the modernized Green Beret armies are attacking the castle. Protect the castle by shooting down the Green Beret forces and the air supplies to gain more experience to earn new weapons.