MAP21: Lunar Mining Project (PlayStation Final Doom)

MAP21: Lunar Mining Project is the twenty-first map of PlayStation Final Doom and is the eighth level of the TNT episode. It is based on the PC version of MAP23: Lunar Mining Project (originally designed by Paul Turnbull for TNT: Evilution) as an adaptation with colored lighting applied and some simplifications done on level geometry, texture set and monster types count. Changes for the PlayStation port were authored by Tim Heydelaar. It uses the music track "Breath Of Horror" by Aubrey Hodges.

Essentials
You start in a long hallway the southern portion of the level, with the exit door (locked with a blue key) behind you. Go through the door at the east end of the hallway, and you will find yourself in another hall with four doors on the east side. Go through the third door and you will find the yellow keycard sitting on a desk.

Go back to the hallway you were in a moment ago and go north through two more doors, arriving in a room with a large desk (the red keycard sitting on the desk is not required to complete the level). Go to the north-west corner of the room and take the lift down to a rocky cavern. Activate another lift on the east side of this room which will take you to a higher tunnel, then follow this tunnel and jump over two holes until you drop into a large cavern with a nukage river. Cross this river and take the blue keycard.

Now backtrack to the start of the level (watching out for numerous monsters that teleport in or appear from alcoves) and open the exit door. Kill the chaingunners and revenant in the exit room (if you are playing on Hurt Me Plenty or Ultra Violence skill levels), then press the switch at the south end of the room to finish the level.

Other points of interest
The red keycard found in the northern room, behind the yellow doors, is used to access the outdoor area in the center of the level. Here you can find a rocket launcher at the top of the circular staircase in the nukage pool, as well as a super shotgun between two brick pillars.

Secrets

 * 1) In the room containing the yellow keycard, there is a medikit with a distinctive wall texture behind it. Open this wall to find an imp and another medikit. (On HMP/UV, you will find also a box of shotgun shells).
 * 2) In the room with the red key, one of the computer panels on the north wall has brightly lit screens. Open this panel to find a stimpack and box of shotgun shells, as well as an imp on HMP/UV.
 * 3) There is an octagonal room on the west side of the cave area, with an invulnerability powerup on a table. Sprint-jump onto the table to get the secret.

Bugs

 * Six shotguns in the level are only accessible in deathmatch, but they are not flagged as multiplayer-only. This bug is inherited from the PC version of the level.
 * At the eastern entrance to the underground cave, the bottom texture of the first tunnel ahead is not set resulting in, specifically random flickering. This could be an oversight from adjusting the heights of the tunnels to accommodate the shorter elevators.

Room design

 * All switches use a skull switch on metal wall texture.
 * Some brightly-lit sectors (representing lights cast through windows) are removed from the hallways around the outdoor area.
 * The brick pillars around the edges of the outdoor area are changed to metal supports.
 * The chairs in the north room, behind the yellow doors, are replaced with small staircases.
 * The lifts to the northern caverns are much shorter, as textures will only tile vertically once in PlayStation Doom.
 * The tall green firesticks in the north-western room (with the invulnerability powerup) appear on all skill levels, rather than just HMP/UV.
 * The archway with a sky texture used to exit the level is removed, and replaced with a switch that must be pressed. A teleport trap which causes a baron of Hell to appear in front of the archway on HMP/UV is retained, but the trap is somewhat redundant on PlayStation as the monster protecting the switch can be seen immediately.

Monster placement

 * Lost souls and spectres are removed without replacement.
 * Barons of Hell are replaced with revenants.
 * The arch-vile in the central outdoor area on HMP/UV is replaced with a revenant.