Level 13: The Crypt
Back to Final Doom
From the Start clear out the Lost Souls and press both Buttons. Each of them will lift up the door half way. Go through and grab the Yellow Key from the center of the room. Four Mancubus will appear from inside the pillars. You may want to use the BFG to get rid of one or two of them quickly.
Open the door to the east and after taking out the enemies head down the steps. The silver teleporter in the small building is actually a lift that takes you down to the ground level. Take it down but watch out for the 2 Hell Knights waiting for you at the bottom.
Around to the right you’ll find Chaingunners, an Arachnotron and a Mancubus. Hug the wall to the left to trigger the Baron of Hell.
Kill it and then climb up the ladder where the Baron came from. Head up the steps and use the BFG when you enter the next room to quickly kill the Arch Vile and Chaingunners. Head around behind the wall to the south and flip the Switch.
Head back to the ground floor and quickly turn to the right. Flip the Switch to lower a pedestal with the Soul Sphere on it. This is Secret 1.
Go through the teleporter to the left marked by the blue bars. It Should have lowered when you pressed the Switch in the room with the Arch Vile. You’ll be taken to a balcony with the Blue Key.
Dash back across to the path and head back to an earlier room. Go through the Yellow Door to the west and then the Blue Door to the south. Watch out for the teleporting Baron of Hell. This opens the door in the main room to the north.
Head through the door you just opened to the north and start taking out the enemies in the room with the pool. When you enter turn around and kill the Revenants that appear from a room behind you.
Use rockets to take out the 2 Arch Viles in the windows. One of them is guarding a Megasphere. Press the Switch in front of the door and quickly turn around. The door will open, releasing a third Arch Vile and a few other enemies. Use the BFG to take him out and grab the Megasphere before stepping into the Exit in the small pool.