The alien invasion is here! They have taken over most of the US and destroyed almost every city and all but one platoon of soldiers. Take over that platoon of soldiers and fight your way across the US to the east, and defeat the alien's base and save the world! Use your mouse to aim your gun and fire your guns. As you gain gold from the aliens, buy more troops to add to the number of guns you control. As you begin to run out of ammo, either collect the bullets the aliens drop or hit spacebar to spend 50 gold on more bullets.