To use the Doomsday Engine you will need at least one of the following
original data files: Doom, Ultimate Doom, Doom II, Final Doom, Heretic,
or Hexen. Run the game as follows:

$ doomsday -game jdoom -file /path/to/iwad/doom.wad

Additionally, if you have the audio/timidity port installed, the engine
will automatically make use of it at runtime playing the associated
game's MIDI music.