Maps E1M1 and E2M1 along with the scripts, EDF and mapinfo were made by anonymous. Please reuse them as you like. 

All the new texures/sprites/sounds are from Doom/Doom II, CC4, Heretic, Hexen or Hexen 2, or simple edits thereof, except the "eyes" textrue which was made new. 

The D_E1M1 music is "Rise From Your Grave [Reconstructed by 8-BeatsVGM]"
https://www.youtube.com/watch?v=hvfRu91nbmw&list=PLIFgc93rh88KCnjCz44FyhtAmuZL7COn6&index=15

The D_POWER music is "Power Up!" from the Geneis version of Altered Beast, ripped by 2ch-H
https://www.zophar.net/music/sega-mega-drive-genesis/altered-beast

The D_INTER music is "Mouth of the Oubliette" by dustboxednorth
https://modarchive.org/index.php?request=view_by_moduleid&query=207855