Very good games for *NIX platform:

>> wesnoth
Homepage: http://www.wesnoth.org/
Description: Battle for Wesnoth - A fantasy turn-based strategy game

>> freeciv
Homepage: http://www.freeciv.org/
Description: multiplayer strategy game (Civilization Clone)

>> enemy-territory
Homepage: http://www.idsoftware.com/
Description: standalone multi-player game based on Return to Castle Wolfenstein

>> simutrans
Homepage: http://www.simutrans.de/
Description: A free Transport Tycoon clone

>> freecol
Homepage: http://www.freecol.org/
Description: An open source clone of the game Colonization

>> supertux
Homepage: http://super-tux.sourceforge.net
Description: A game similar to Super Mario Bros.

>> widelands
Homepage: http://widelands.sourceforge.net/
Description: A game similar to Settlers 2

>> openttd
Homepage: http://www.openttd.com/
Description: OpenTTD is a clone of Transport Tycoon Deluxe

>> lbreakout2
Homepage: http://lgames.sourceforge.net/index.php?project=LBreakout2
Description: Breakout clone written with the SDL library

>> bomberclone
Homepage: http://www.bomberclone.de/
Description: BomberMan clone with network game support

>> pingus
Homepage: http://pingus.seul.org/
Description: free Lemmings clone

>> abuse_sdl
Homepage: http://www.labyrinth.net.au/~trandor/abuse/
Description: port of Abuse by Crack Dot Com

>> barrage
Homepage: http://lgames.sourceforge.net
Description: A violent point-and-click shooting game

>> bygfoot
Homepage: http://bygfoot.sourceforge.net/
Description: GTK+2 Soccer Management Game

>> ufo-ai
Homepage: http://www.ufoai.net/
Description: UFO: Alien Invasion - X-COM inspired strategy game

>> astromenace-bin
Homepage: http://www.viewizard.com/astromenace/index_linux.php
Description: Modern 3D space shooter with spaceship upgrade possibilities