Doom/E2M2: Containment Area

Firstly, you can check the corner in the right at the edge of the entrance alcove for a security vest if you need it. The shotgun on the high crate you see in front of you can be obtained by throwing the switch next to the window on the left-hand wall. Kill the Imps as they appear. Make sure to fully explore this crate-filled area - you will need the extra shotgun shells and bullets, plus as a backup around the first left-hand corner you can grab a Berserk powerup which will serve you well in case you run out of ammo (and you don't have the Chainsaw yet). If you are reduce to fighting with your fists, make sure you retreat after each hit attempt as enemy melee attacks hurt, especially on Ultra-Violence.

Look at your map - you want to head to the bottom of the crate area. Down here, there are two entrances - one leads to an open room with four columns, the other into a tunnel coming off from that room. Once you're in there, dispatch the Imps and head to the one opposite the entrance. Hit the switch to open the door. Step onto the open floor beyond and it will raise up to form steps up to the lit crossroads up ahead. Kill all the Imps and Demons that initially appear. Once it looks clear, go right, then right again at the corner. Head across the two long rooms with the hurting floor down the middle (don't forget to pick up the goodies as you go). At the far end of the third one is a tunnel which leads to a small room containing a Backpack on a lit pedestal. Grab it, and a wall will close behind you - followed by the wall in front opening to reveal more Imps and Demons. Kill them all. You will notice that in the room beyond, where the enemies came out of, there is a differently-patterned wall section to the right. You can open this to reveal more enemies, but on the plus side the wall at the back of the room where the backpack was will open. There is another similar wall on the right-hand side of the room you just revealed; beyond this secret wall is a series of Imps, and a door which leads back into the four-pillared room.

Go back to the lit crossroads and go left this time. Take another left and you'll find a room with blood-coloured slime in it, and the yellow keycard beyond it on an unreachable ledge. Thankfully, you can follow the pattern of lights on the roof to reach it; as you step off the platform another will rise out of the slime. Once you've got the keycard, turn around and head to the odd section ahead - there are three circular bits with platform sections rising up and down below it. You can get in the first one and you'll find a secret tunnel which contains lots of health bonuses, and will take you to near the blue keycard door off from the four-pillared room. Beyond the other two are some more goodies. You can check around this area for several goodies including a cell pack for the plasma rifle and some combat armour.

Secrets
There are 12 secrets in the map.
 * 1) In the starting box area, head to the west, then head south.  Approaching what appears to be a dead end will lower the boxes to reveal 2 health kits. (Sector 236)
 * 2) When you reach the soutern-half, take a left and head to the perpitually moving platforms.  In the northern-most set, look for a hidden tunnel leading north.  Contains health bonuses and shotgun shells.  (Sector 60)
 * 3) Upon entering the southern half, take a right, and take the first exit to the right.  Jump across the blue circled floor, until you reach the third set.  Exit this room in the opposite corner, and go down the corridor. The secret is only one step down, but a backpack is in view. Approaching the backpack temporarily closes a door behind you, and taking the backpack opens a monster closet. (Sector 128)
 * 4) Opening the back wall of this monster closet leads to another room.  The room serves only as a shortcut back to the central area. (Sector 137)
 * 5) From this shortcut, open a wall on the south to get some rockets, health and a computer map. (Sector 140)
 * 6) The plasma gun is a secret. When you reach the southern-part with the white floor, take a right, and a left to the brown floor.  Enter the hexagon-tiled room, and flip the switch on the first column; the second column further in the room will lower. (Sector 45)
 * 7) With the yellow key, head to the north-east corner of the map.  Enter the north section of the room, and three columns will rase, each with a switch.  Flip the right switch to open the central door in the previous room to reveal a rocket launcher.  (Sector 160)
 * 8) As the previous secret, but flip the left switch. This opens a monster closet with ammo. (Sector 146)
 * 9) As the previous secret, but flip the center switch. This opens a monster closet with ammo.  If you want to access the backpack on the center switch, walk into any of the rooms. While the columns will lower, the switches should remain functional. (Sector 164)
 * 10) With the yellow key, head to the north section of the map, next to the start.  Enter the central room, and flip the north switch to get the chaingun.  (Sector 176)
 * 11) In the crushing ceiling section to the south of the map, there is an opening in the left wall of one of the crushers.  This leads to a chainsaw. To get the chainsaw without opening the doors, simply walk on the platform from the south-east corner, and avoid crossing the center.  (Sector 26)
 * 12) Past the crushing ceilings, in the blue-key room, walk on the lit southeastern corner.  Quickly run to the supercharge as it lowers and before it raises back up. There is only one chance to obtain this secret; if you miss it, it's lost forever.    (Sector 109)

Multiplayer

 * There is a second plasma gun, behind the column containing the first one.
 * The supercharge in the blue-key room is a secret, and if handled by another player incorrectly (or selfishly), it may be permanently locked as well. If respawning is enabled and you wish to access the powerup again, wait in the lift after collecting the charge, and press the switch to return.