GTA: Zombie Riot
When the zombie apocalypse happened, no one was prepared so most people have died. Afterwards, police and soldiers were deployed to the area. Both parties were not prepared and most of them got killed. Soon, they find other people fighting for their lives and they recruit them too. In this game, you are going to recruit some men and try to defend the border. Each lane would need someone to defend it. You would unlock more men as you move forward to the game. The game would be harder as you make some progress, so keep buying those upgrades to make it easier for you.