Underground Zombie - Version 1.4 The apocalypse has arrived, and thousands of zombies overrun the city. Just a few people are able to resist the invasion. One of these brave fighters is now in the dungeon, and continues to hold the line ... Who knows how long it will hold. You must help him survive for 10 nights, and shoot all zombies you encounter. Each enemy killed will earn experience points, which make it possible to improve the skills of your character. Also in the game there is a Tower Defense element in which killing enemies earns money so you can build defensive traps or buy guns.