GTA: Decision 3
You have been successful to liberate two cities so far. Now, you are looking to liberate another city. You are fortunate enough to find some allies since the city is not a complete lost. The locals are still fighting in this city and they would appreciate some help. Kill any zombie that you encounter and try to help other survivors in the area. That is pretty much the objective of the game. Of course, you would need to do a recon mission every now and then and form an outpost. This would help in controlling the zombie infection.