Linux Games

0 A.D. [http://wildfiregames.com/0ad/]

$ sudo add-apt-repository ppa:wfg/0ad
$ sudo apt-get update
$ sudo apt-get install 0ad

Urban Terror [http://www.urbanterror.info/docs/texts/110/]

Alien Arena [http://red.planetarena.org/]

$ sudo apt-get install alien-arena 

Vertigo [http://www.vertigo-game.com/]

just download,unzip and run