MIDI Credits:
(Please not that some composers' preferred name might have changed since I last checked)
MAP01: Techbase Trance by Fookerton
MAP02: Hangar from Cyril Cyberpunk
MAP03: Ghosts in the Walls by Stewboy
MAP04: Aorta by Tristan Clark
MAP05: Shotgun Shawrma by Rogue Akai & Sumo
MAP06: Fire Hive by Jimmy
MAP07: Junkie Smack by Merk Klem
MAP08: Alien Jungle by Stewboy
MAP09: Silicone Dust by Jimmy
MAP10: First Time for Everything by Crunchynut44
MAP11: Ghost Grinder by Jimmy
MAP12: Broken Mirror by Tristan Clark
MAP13: Astral Dreadnaught by Jimmy
MAP14: I Don't Want You To Leave (Regretful Edit) by Viscra Maelstrom
MAP15: Ripsaw by Jimmy
MAP16: Dave D Taylor Blues remix by Jay Reichard
MAP17: The Eternal Emptiness by Myrgharok
MAP18: Hyperion Methane Mine from Descent
MAP19: Grandfather Clocktower by Viscra Maelstrom
MAP20: Against God's Will by Eric Baker
MAP21: Featherfall by Stewboy
MAP22: The Face of Wrath by Stewboy
MAP23: All Systems Agogo by Alfonzo
MAP24: The Caco's Best by Megasphere
MAP25: Riot Squadron by Jimmy
MAP26: The Doom World is Flat by decino
MAP27: Crawler by AD_79
MAP28: Weather Warning by Jimmy
MAP29: Rat Men's Station by ZenMystic
MAP30: The Knives that Carved the Monolyth by Cammy

Intermission: Quell the Beast by Jimmy
Text Screen: Zombieman Blues by Fookerton

SKY1 made by Mechadon
SKY2 derived from photo made by @BadAstronomer on twitter. Edited by many people,
mostly Jimmy
SKY3 made also by Mechadon (Then resized)

ENDOOM by Peccatum Mihzamiz