SlackBuildsOrg/games/prboom-plus

PrBoom+ is a Doom source port developed from the original PrBoom project.

Features uncapped framerate, widescreen aspect ratios, soundfont support,
variable gamespeed, re-record, walkcam, chasecam, full full mouselook, fov and
other features along with full compatibility with the original Doom/Doom2
engines.

FluidSynth, needed for soundfont support, is a recommended optional dependency.
To get soundfont support, edit ~/.prboom-plus/prboom-plus.cfg. Set
snd_midiplayer to "fluidsynth" and snd_soundfont to the path to the soundfont
(.sf2) file.

The documentation refers to a directory into which an IWAD file (doom.wad,
doom2.wad, tnt.wad, plutonia.wad, or the shareware doom1.wad) may be placed.
The IWAD directory is /usr/share/games/doom.