In REDDOOR, the player is immersed in a post-apocalyptic world overrun by zombies. The objective is to survive solo against endless rounds of the undead by strategically opening and clearing doors and using a variety of weapons, perks, utilities, and power-ups. The player earns points from killing zombies, which can then be used to purchase guns, perks, and unlock new areas, or turn on the power. The zombies enter the player's space through special "RED DOORS", and the game will end when the player