Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
Left 4 Dead - Left 4 Dead is an Engaging, Action-Adventure, Horror-Survival, FPS (First-person Shooter), Co-op, Single and Multiplayer video game created and published by Valve.
Counter-Strike - Counter-Strike is a PC-exclusive FPS video game developed by Valve Corporation.
Amnesia: The Dark Descent - Amnesia: The Dark Descent is an addictive, Horror-Survival, Exploration, Dungeon Crawling, and Single-player video game developed and published by Frictional Games.
Quake - Quake is a series of first-person shooter video games released by id Software.
Resident Evil - Resident Evil is an Addictive, Horror-Survival video game which is inspired by the movie named as Resident Evil.