GTA: Army of the Dead
There is a disturbance going on a little town and you and your team has been sent to control the situation. Your team called you for back-up, so got there as fast as you can. Hopefully they are still alive when you get there since they are fighting the army of the dead. Shoot the weak spot of the enemies. Weak spot are found in several areas of the body and you need to remember them. To make it easy, you just need to hover your mouse over the enemy and you would see the mouse pointer turning red. That would be the weak spot and you need to shoot it.