MAP04: Combine (PlayStation Final Doom)

MAP04: Combine is the fourth map of PlayStation Final Doom, and the fourth map of the Master Levels episode. It is based on the PC version of MAP01: The Combine from the Master Levels for Doom II, with modifications to accommodate the PlayStation's framerate and storage capacity limitations and add enhancements such as colored lighting. It uses the music track "Larva Circuits".

This level is known as The Combine on PC and its author was Christen Klie. Changes for the PlayStation port were authored by Tim Heydelaar.

Essentials

 * 1) From the starting area, go into the brick tunnel visible on your right. Go north and open the door, leading to a room with a staircase running round its perimeter.
 * 2) Climb the staircase and go through the door on the north side of the western wall. As soon as you go through this door, turn right and drop off the ledge, then go through the door in front of you.
 * 3) You will be in a room with gray computer screens. Go down the steps and take the blue skull key from the flashing plinth.
 * 4) Return to the room with the round staircase and open either of the doors on the north wall. Drop into the nukage pool and head west until you reach a wall with a thin staircase. Climb up it, open either of the blue doors and go into the teleporter behind them.
 * 5) You will arrive on a plinth with the red skull key. Pick it up and drop to the ground.
 * 6) Return to the room with the round staircase and open the red door on the east wall.
 * 7) Follow the narrow walkway south and go through another door to a long room with steps. Press the switch in the south-west corner of this room.
 * 8) Go back to the room where you found the red key and open the red door on the south wall. Go through the open wall on your left and a switch will be revealed in front of you. Press this switch to reveal another switch in the south-west corner of the room. Press this second switch to lower the plinth with the yellow skull key, then quickly run round to collect it before the plinth rises again.
 * 9) Go back to the starting area and open the door in the south-west corner. In this room, shoot the switch inside the small brick building, then open the yellow door at the north end of the room and press the switch behind it to finish the level.

Other points of interest

 * Armor and a super shotgun can be found in the north-east corner of the starting area. Approaching these items causes three chaingunners to teleport into the area on Ultra Violence skill level, three shotgun guys on Hurt Me Plenty, or three zombiemen on I am a Wimp/Not Too Rough.
 * A rocket launcher can be found in the center of the room with the blue skull key.
 * A chaingun can be seen on a platform in the large northern room with the nukage pit, at the top of the steps. In the room with the round staircase, go through the door on the west side of the north wall and you will see a switch on your left. Press this switch to lower the platform, then run round to the chaingun before the platform rises again.
 * A plasma gun is placed on a small platform west of the red skull key. Be careful as taking the gun may trigger a crusher trap; this can be avoided by approaching the plasma gun slowly so that you just touch it.
 * A partial invisibility powerup can be found in the south-east corner of the area with the red skull key. You can reach it using a lift on the west side of this area.

Secrets

 * 1) The area in which you begin the level is flagged as secret, and is thus impossible to miss. (sector 20)

Room design

 * All switches use a skull switch on metal wall texture.
 * Scrolling silver textures are replaced with computer textures which do not scroll.
 * The computer textures used in the alcoves overlooking various rooms are replaced with dark screens.
 * The round staircase north-east of the starting area has fewer steps.
 * The height of the central room (with two large staircases) is slightly reduced.
 * The blue skull key is placed on a raised plinth with a rapidly flashing light.
 * The height of the tall outdoor area (south-west of the red skull key) is slightly reduced.
 * The narrow walkway behind the eastern red door is wider.
 * The long room east of the starting area is shorter, removing the level's only chainsaw pickup. The ledge leading to the switch at the end of this room is wider, and a teleporter is added to the nukage pit so that players can escape if they fall in.
 * The room with the yellow skull key only requires two switches to be pressed instead of five.

Monster placement

 * An imp is removed from the room with the narrow walkway, behind the eastern red door.
 * The level's only spectre, found in the south-eastern corner of the level, is removed without replacement due to that room being shortened.

Player spawns
This level contains four spawn points:
 * 1) facing south-west. (thing 28)
 * 2) facing east. (thing 37)
 * 3) facing north. (thing 40)
 * 4) facing west. (thing 42)

Things
This level contains the following numbers of things per skill level: