Alien Swarm is an action game developed by Valve Corporation and released on Microsoft Windows.

Deathmatch Classic is a shooter game developed by Valve Software and released on Microsoft Windows.

Ricochet is an action game developed by Valve Software and released on Microsoft Windows.

Counter-Strike is an online first-person shooter game developed by Valve Software for the Microsoft Windows, Mac OS, and Xbox. Originally a mod for Half-Life by Minh "Gooseman" Le and Jess Cliffe, Valve eventually began to help in its development and bough the rights to it in 2000.

Half-Life is a shooter game developed by Gearbox Software, Valve Software and released on Mac OS, Microsoft Windows, PlayStation 2.

Team Fortress also known as TF  is a FPS game (First Person Shooter) developed by Valve and released April 7th, 1999. This game was originally released for Windows. The game itself conatains a number of teams and 9 different classes from you to choose from.