Warframe!

Team Fortress 2 (TF2) is the sequel to the game that put class-based, multiplayer team warfare on the map. One of the most popular online action games of all time, TF2 delivers constant free updates including new game modes, maps, equipment and, most importantly, hats.

Urban Terror started as a realism based "total conversion" mod for Quake III Arena. Nowadays, Urban Terror is played using the free, stand-alone, ioquake3 engine modified, which doesn't require Quake III Arena, in addition to being an add-on to id Software's Quake III Arena.

One of the most popular online action games of all time, Team Fortress Classic features over nine character classes -- from Medic to Spy to Demolition Man -- enlisted in a unique style of online team warfare. Each character class possesses unique weapons, items, and abilities, as teams compete online in a variety of game play modes.

Gang Garrison 2 presents the player with 9 unique classes to use in frenetic, cooperative multiplayer action in a stylish and unique 8-bit style. Battle with your friends or others you encounter online through a whole range of vibrant maps; TF2 maps reimagined in 2D as well as a multitude of maps with all sorts of different looks and settings, all of which have been dreamed up and constructed by members of our community. We've made a huge effort to provide simple, bugfree custom map support, so that anyone with a paint application can put together a map and test it themselves with our Garrison Builder utility. We also gladly encourage Gang Garrison modifications; many successful mods have been incorporated into the game as new features. »

Loadout is an outrageous new multi-player shooter that’s all about the guns, baby! Build a massive variety of absolutely insane weaponry - billions of combinations - totally customized, totally unique, and totally deadly.

Warface is a free-to-play online first-person shooter developed by Crytek Kiev and co-produced by Crytek Seoul and Crytek Frankfurt with Crytek UK developing the Xbox 360 port.

A 6 vs 6 first person shooter, Gotham City Impostors is a multiplayer game unlike any other, giving players the opportunity to rebel against conformity as they customize their own characters. Posing as amateur vigilantes or villains, gamers will create their very own Bats and Jokerz characters using unprecedented customization options including insane costumes, homebrewed gadgets and a wide range of traditional and imagined weapons.

Block N Load is a 5 vs. 5 team-based FPS shooter similar in style to a combination of Minecraft and Team Fortress 2.

A video game based on the ABC television series Lost that was released for the PC, Xbox 360 and PlayStation 3 on February 26, 2008. The game was officially unveiled at Comic-Con 2007.

Mission Against Terror is a free-to-play, first-person shooter (FPS) where two opposing teams must complete their given objectives within a time limit, using real-world weapons in a variety of maps and locales against players from around the world. Players can join clans, team up with friends against computer-controlled bots, and even fight a Dragon Emperor.

Across any terrain, with any weapon, against any opponent—the war must go on! Test your prowess with modern first-person shooter action in intense warzones ranging from labyrinthine urban locales to dusty desert battlefields. The gear, combat, and settings are designed to create an exceedingly realistic and fast-paced style of gameplay.