Chocolate Doom is a Doom source port that accurately reproduces the
experience of Doom as it was played in the 1990s.

Starting with version 2.0.0, Chocolate Doom also supports Heretic, Hexen,
and Strife.

To play chocolate-doom, you need at least one of:
  doom2.wad from Doom II
  doom.wad from Registered Doom or Ultimate Doom
  tnt.wad or plutonia.wad from Final Doom
  doom1.wad from Shareware Doom (doom_shareware_data on SBo)

For chocolate-heretic:
  heretic.wad from Registered Heretic
  heretic1.wad from Shareware Heretic (heretic_shareware_data on SBo)

For chocolate-hexen:
  hexen.wad from Registered Hexen
  hexdemo.wad from the Hexen demo (hexen_demo_data on SBo)

For chocolate-strife:
  strife1.wad from Registered Strife

Place the WAD file(s) in /usr/share/games/doom.

freedoom doesn't work with Chocolate Doom. Neither does strife0.wad from
the Strife demo. Chex Quest might work (not tested by SlackBuild author).