Brutal Doom: Hell on Earth Starter Pack

The Hell on Earth Starter Pack (Later known as Extermination Day) is a 32-level megawad add-on for Brutal Doom, created by Marcos Abenante (Sergeant Mark IV) and initially released on December 31, 2015. It is intended to be loaded with Doom II or Freedoom, using the included version of GZDoom which is pre-configured for play.

Level/episode list
Episode 1 - Hell on Mars
 * MAP01 "Hangar"
 * MAP02 "Nukage Processing"
 * MAP03 "Water Treatment Plant"
 * MAP04 "Communications Center"
 * MAP05 "Marine HQ"
 * MAP06 "Nuclear Power Plant"
 * MAP07 "Staging Area"
 * MAP08 "Lab Complex Entrance"
 * MAP09 "Bio Labs"
 * MAP10 "Portal Testing Labs"

Episode 2 - Battle of Los Angeles
 * MAP11 "Return to Earth"
 * MAP12 "Depot"
 * MAP13 "Industrial District"
 * MAP14 "Warzone"
 * MAP15 "Twisted Neighborhood"
 * MAP16 "Dead Streets" - secret exit to MAP31
 * MAP17 "Final Destination"
 * MAP18 "Eye of the Storm"
 * MAP19 "Push"
 * MAP20 "The Tower"

Episode 3 - Behind Hellish Lines
 * MAP21 "At Hell's Gate"
 * MAP22 "Blood Swamp"
 * MAP23 "Stronghold"
 * MAP24 "DIS"
 * MAP25 "House of the Hell Nobles"
 * MAP26 "Necropolis"
 * MAP27 "Cathedral"
 * MAP28 "Sacrificial Grounds"
 * MAP29 "Bloodfalls"
 * MAP30 "Devil's Domain"

Secret Levels
 * MAP31 "Los Angeles Holocaust" - secret exit to MAP32
 * MAP32 "Wolfenstein"

Unfinished Levels These levels can be accessed via console, but they are incomplete and left out by the author. They may be officially added to the project in a later version.
 * MAP00 "Unnamed"
 * MAP05B "Unnamed"
 * MAP13B "Unnamed"