Zombie Crush - a world in which you control a tank and your job is to push a zombie, you have met along the way. In this game you push zombies, leaving a wet spot on them, thus helping the city get rid of the pesky creatures.
Zombies need to push the front of the tank, otherwise they are approaching from the side and attack the tank. The more attacks on the tank, the greater the damage and the early exit of the tank failure.
As for the upgrade in the game there is a garage where you can both strengthen tank armor, and patch up the tank.