PrBoom is a cross-platform version of the classic 3D first person shooter Doom from id Software. Originally written for win32 (MS Windows), PrBoom has since been ported to Linux and many other platforms. It offers a number of enhancements over the original game, including OpenGL rendering and high video resolutions, while attempting to remain true to the original Doom in terms of play. You will need the original Doom data, unless you install the FreeDoom package (see below).
PrBoom is available from the standard repos:
# pacman -S prboom
If you do not have the original Doom data available to play PrBoom, you can install the freedoom package from the AUR.
$ yaourt -S --aur freedoom
This will place the data in the correct directory, so you can just start PrBoom and frag away!