The machines took the cities. The last humans hold out behind the walls of one city block. Shoot back, rebuild, and take the city back one block at a time. No energy, no waiting: play as much as you want.
Come back every day. Miss a day and you just pick up where you left off.
Three new ones every day.
Rebuild your camp piece by piece.
Sound starts after your first tap (browsers require it).
Pick one. It lasts until you get home.