GTA: Final Siege
The world war in a constant war and when they got tired of one another, they launched atomic bombs that wipe out most of the world's population. Most of the survivors have mutated into zombies. Others become their prey. Years have passed and most cities have succumb to the rampaging zombies. Now, only one city is left. The game is played via mouse and the idea here is to build more towers to defend the city. Each tower has its own strength and weakness. You need to strategise where your tower should be to defend the city well.