Although the most professional and sophisticated of the bunch, there is a lot more to gaming on Linux than Civilization: Call To Power. Two other big-name games are the highly popular Quake series (which were the first of the really big names to make their way over to Linux) and Hopkins FBI (http://www.hopkinsfbi.com/). The latter is by MP Entertainment, a French company, and is a shoot-em-up game that uses hand-drawn animation. It is available now.
According to a contact at MP Entertainment, they are working on a new project for Linux: a “team fortress/Special Ops”-type game, with single- and multi-player (1-128 players) modes. A beta version of the game will be on-line in October and they expect to release the final version sometime in January 2000.
They are also working on Hopkins FBI 2, but they don't know if it will be ported to Linux yet. They are awaiting the result of the sales of Hopkins FBI for Linux.
The latest in the well-known Quake series is Quake 3 Arena—a multi-player shoot-em-up game. The test version was released for Linux in early May. It requires a 3Dfx Voodoo 2 card and the 3Dfx Linux Glide drivers. You can check out id Software's Quake 3 Arena page at http://www.quake3arena.com/.
A few other projects designed to make running existing games on Linux easier are available. The Sarien AGI (http://homepages.ihug.com.au/~entropy/agi/) Interpreter, which allows classic Sierra titles such as the early Kings Quest games, was in early development at the time of this writing (early May). A similar project, LAGII (http://www.zip.com.au/~gsymonds/LAGII/), claims to have the ability to run several of the older Kings Quest games already.
A number of projects, including CIV:CTP, Hopkins FBI and the MpegTV Player 1.0, have used or will use the SDL package for graphics and audio. SDL, Simple DirectMedia Layer, is a portable library that runs on Linux, Solaris, Win95 and BeOS. You can find out more about this library, as well as links to other projects that have used it, at http://www.devolution.com/~slouken/projects/SDL/index.html. Sam Latinga, the main developer of the CTP project, developed SDL.
Of course, you can also get some well-known games, such as StarCraft, to run under WINE, the Windows pseudo-emulator. (It is not really an emulator, but it's simpler just to refer to it that way.) Information on how to do this can be found in various places, but you should probably start at Linux Games (http://www.linuxgames.com/) or Linux Game Tome (http://www.happypenguin.org/news). Be warned, however, that if you're running a high-end game like StarCraft on a Windows emulator over Linux, you will need a fairly fast system with lots of memory. Games, by their very nature, are power-hungry.