The world is almost entirely ruined. Zombies have come, and humans are now forced to hide behind fortified walls, always keeping their guns at the ready to pull the trigger if there is another snarling rotten head anywhere close. This is a harsh world, and surviving in it is no piece of cake. As a new human leader, you have to ensure the wellbeing of the colony. Provide your people with food, water, medicine and weapons. None of the zombies should be able to get over these walls!