Game title: Zombie Defense
There are many people on earth. Over a hundred billion people have already died in the past. This is an incredible and realistic combination of tower defense and zombies. You must save the remaining people from extinction. This is an astonishing strategy. Completes missions and collects in-game currency to buy the necessary equipment, technologies, and upgrades. There are several levels of difficulty. After each mission, unique upgrades are provided for you to take advantage of.