MAP01: The Catwalk (Master Levels)

The Catwalk is a map that is part of the Master Levels for Doom II and is the fifth map of the first episode in the PlayStation Doom port. It was designed by Christen Klie, and is contained in the file CATWALK.WAD.

Essentials
From the starting position (A), head east. Platforms will start moving up and down. In the water cave-like area (B), step on the light lamp in the middle and press switches in the south, then in the east and finally at the north. Head to the east alcove where you have pressed the switch. In that place (C), drop down and press the switch to lower the yellow key stand. Return to the top (C) by pressing use on the computer panel and going through the cave (B).

Once you have got the yellow key, head to the western portion of the map through the starting place (A). Platforms will start moving up and down. At the small outside area, open either yellow door. Press the switch in the south to make a bridge in the slime area (D). Walk downstairs and, in the slime area (D), get to the bottom by continuing downstairs. Walk on the narrow bridge to the teleporter. Press the switch. This will lower two stands, one of which contains the red key. Use the teleporter again to return to the start (A).

Return to the cave (B) and use the northern alcove. Head to the southern part of this place where you will open the yellow skull bar and press the switch to reveal the northern place (it also unlocks the door in the beginning). Head to that small outside place. Press the switch in the south to build up a staircase. Lower the northernmost computer panel and get to the teleporter through the other panels. In the very similar but other place, grab the key and return to the teleporter.

Enter the freshly opened area to the tall slime pool area. Go on the bridge to the very north quickly, since it melts down to the pit, and you can no longer get back to the southern part and the places that are entered there. In the north, open the red door. Flip the switch for the end.

Secrets

 * 1) While inside the exit room, shoot at the middle of the east wall to open access to a hidden area. (sector 227) Inside, you will find twelve armor bonuses, three medikits, a soul sphere, a box of bullets, two shell boxes, a backpack, and a switch near the center.  Triggering this switch opens a door in the northeast of this area, allowing access to 15 energy cells.
 * 2) While inside the exit room, shoot at the middle of the west wall to open access to a hidden area. (sector 251) Inside, you will find two sets of four shotgun shells, a berserk pack in front of a switch, and a switch nearby a pillar blocking access to an energy cell pack.  Flipping the switch behind the berserk pack enables access to the cell pack, as well as a hallway accessed from the center of the area ending in a switch.  Pressing this switch lowers a pedestal with a megasphere on it in the southeast of the area.  Pushing the switch near the pillar blocking access to the cell pack opens access to a BFG9000, as well as a doorway in the northwest leading to another switch near the center of the area.  Activating this last switch opens the nearby wall, revealing five shotgun guys and four rocket launchers, and also unlocks access to the megasphere.

Bugs
The door to the tall slime area can be opened once the player has the yellow key, but before they have the red key. If the player crosses the bridge across the area before picking up the red key (causing it to lower), they will become stuck on the far side and be unable to complete the map.

Routes and tricks

 * You can get the red key without needing to go to the western side. By straferunning you can pick up the red key on the platform that is not lowered.

Current records
The records for the map at the Doom Speed Demo Archive are:

The data was last verified in its entirety on December 12, 2021.

Player spawns
This level contains five spawn points:
 * 1) facing south-east. (thing 137)
 * 2) facing east. (thing 138)
 * 3) facing west. (thing 139)
 * 4) facing north-east. (thing 162)
 * 5) facing east. (thing 187)

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

Differences between PC and PlayStation versions

 * In the central nukage hall where the catwalk itself is located, two teleporters for getting out are added. Also the catwalk does not melt down when you walk on it.
 * In the south western outside area a chaingun and a box of bullets are added.
 * In the western part of the map in the room behind the yellow doors, an imp is placed and appears on the HMP and UV.
 * In the eastern place where there is the red skull key, three shotgun shells are added.
 * In the southern side of the central catwalk area, two medikits are added.
 * The yellow bar blocking the room to the switch in the eastern part of map now uses skull texture and an additional bar is added.
 * In the northern side of the catwalk area, there are a chaingunner and two Hell knights that appear on the UV skill.
 * In the secret #2 there is a hanging hook (non blood) instead of the hanging victim.

Trivia

 * The track created for the Master Levels for Doom II 25th Anniversary MIDI Pack is humorously titled "Don't Fall Lmao", referencing the relative ease to fall off certain platforms and be forced to start over.