While Nexuiz is not intended to be an eye-candy laden game, it does feature many advanced effects such as coronas, bloom, Realtime World and Dynamic Lighting and shadowing, shaders (with OpenGL 2.0), offset mapping, and High dynamic range rendering. All these effects can be turned off to make the game run on older hardware. Nexuiz has such a range of effects that enabling all of them would result in an unplayable experience, apart from on the most cutting-edge of hardware.
Nexuiz is primarily multiplayer (though it includes a full single-player campaign, which allows one to play through the various multiplayer game types and maps with bots), and allows for hosting and joining of games. It can also support new gametypes, or whole conversions quickly applied to it (much like Quake). Nexuiz supports most, if not all, Quake modifications (although with varying functionality). Currently there are a few custom mods and maps used.
[More Info]
Download Nexuiz and Mappack to your Desktop.
Download
Code:
mkdir ~/.Games cd ~/Desktop unzip nexuiz-242.zip -d ~/.Games unzip nexmappack_r2.zip -d ~/.Games/Nexuiz
Done.
Download nexuiz.png to your Desktop.

cd ~/Desktop
mv nexuiz.png ~/.Games/Nexuiz
alacarte
Go to the Game section in Alacarte and push the New Item button. Fill in;
Name: Nexuiz
Command: /home/USERNAME/.Games/Nexuiz/nexuiz-linux-glx.sh
Comment: Nexuiz focuses on bringing the FPS genre back to the basics with quick, lethal battles and balanced weaponry.
Icon: ~/.Games/Nexuiz/nexuiz.png
You can now launch from Nexuiz by Applications tab —> Games —> Nexuiz
Enjoy!