DayZ - DayZ is an open world multiplayer survival game that tosses you in the midst of a zombie apocalypse.
Savage Lands - Savage Lands is an Amazing, Open World, Role-playing, Fantasy, Survival, Co-op, Single and Multiplayer video game developed by Signal Studios.
7 Days to Die - 7 Days to Die is a post-apocalyptic survival game, during which players must craft shelters and horde resources in order to survive waves of undead enemies. Read more about 7 Days to Die.
Rising World - Rising World offers Open World environment and mixes the elements of Sandbox, Survival, Role-playing, and First-person Perspective Elements.
Project Zomboid - The Ultimate Zombie Survival RPG.
Rust Game - Rust’s world is harsh. The environment is not kind. Bears and wolves will chase and kill you. Falling from a height will kill you. Being exposed to radiation for an extended period will kill you. Starving will kill you. Being cold will kill you.