Level 1
Termination Central

Level 2
The Vaults of Zin

Level 3
The Tomb of Terror

Level 4
Satan's Dark Delight

Level 5
Wind Tunnels

Level 6
Chambers of Torment

Secret Level
The Haunted Halls

There’s not too much to note regarding Termination Central, except that you shouldn’t get too confident if you make it through easily; this level is a cakewalk compared to the rest of the episode. Enforcers, rottweilers, and grunts are the only foes you’ll encounter, so stock up on shells and cells and think of Termination Central as target practice for what lies ahead.

When you come to a divided hallway, take the left branch. At the bottom, shoot the darkened area of the wall to the right to open this secret door

Secret Area 1
Near the beginning of the level, you’ll come to a hallway, which branches into two ramps leading down to the left and right. You’ll have to head right first in order to lower the barrier at the bottom of the left ramp. When walking down the left ramp, notice the dark area of the right wall at the bottom. Hit it to open a secret passage containing a red armor.

Secret Area 2
After making your way through the hallway barriers, you’ll come to a central platform, with a Quad Damage and some radioactive waste barrels. Walk directly between the two exits and look down, where you’ll see a small ledge. Drop to the ledge and walk into an area under the platform with a yellow armor, some health, and some rockets. An elevator at the back will take you to the beams over the platform, where you can grab some shells.

This thin ledge runs between the two exits on the central platform. Drop down to find Secret Area 2

Secret Area 3
From the central platform, drop down into the slime. Swim down and go through the tunnel located near the floor on the back wall. Swim back to the surface and jump up onto the walkway for lots of ammo and health. At the end of the walkway is a teleporter, which will take you a ledge with green armor. Follow the ledge around until you drop down to another ledge, where you’ll find a 100 health kit and a teleporter. Enter the teleporter, then turn around to see another teleporter, which will take you back to the start of the level.

Secret Area 4
Ride up the elevator to the ledge where the gold key is located. You’ll see a Quad Damage on a smaller ledge directly below the key. To access it, go down to the level you entered and jump to the shadow area just to the left of the elevator. Walk along the small ledge to the Quad Damage.

Climb the stack of boxes, then turn to your left. You'll see this distinct wall panel, which is actually the door to Secret Area 4

Secret Area 5
When you reach the stack of metal boxes, go around to the back, where you will find an opening. Walk into the middle of the stack and jump up the boxes until you reach the top. Turn to your left and shoot the section of the wall where there is a gap in the pattern of lights. A door will open to a small room with 100 health.