S.T.A.L.K.E.R. - S.
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
Earth Defense Force 2025 - Earth Defense Force 2025 is an Action-Adventure, Role Playing, Third-person Shooter, Single and Multiplayer video game developed by Sandlot and published by D3 Publisher.
Quake - Quake is a series of first-person shooter video games released by id Software.
Turok - Turok is an Action-Adventure, FPS, Survival, Single and Multiplayer video game developed by Propaganda Games published by Disney Interactive Studios.
Counter-Strike - Counter-Strike is a PC-exclusive FPS video game developed by Valve Corporation.