DayZ - DayZ is an open world multiplayer survival game that tosses you in the midst of a zombie apocalypse.
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
Dead Frontier - Dead Frontier is among the few zombie based video games that you can obtain in your web browser and for free.
Counter-Strike - Counter-Strike is a PC-exclusive FPS video game developed by Valve Corporation.
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.
Quake - Quake is a series of first-person shooter video games released by id Software.