Level 12: Speed
Back to Final Doom
From the Start take out the Imps, go down the steps and open the Door to the building. Go inside and clear out he gunners from around the edges. Watch out for the Arch Vile through a window to the east.
Clear out the Pain Elementals, Cacodemons and other enemies and then drop down to the area to the east. Head through the passage to the left to grab the Yellow Key. Continue up the stairs and dash forwards to the teleporter. You’ll be taken to a ledge on the other side.
Head around to the left and go out to the area on the western side of the map. Clear out the enemies and take the lift up on the south side. You’ll hear the roar of a Cyberdemon. Stand in the corner so that his missiles hit the torch. From here you can take your time to kill him
Hit the Face Button and dash across to the platform with the Cyberdemon for the Red Key. Drop down and take the lift up in the southwest again. Follow the stairs all the way up to the Blue Key in the window.
When you head back down you’ll be teleported to an outdoor area with 2 Arch Viles being constantly teleported. Focus on one of the teleporters and shoot Rockets until they’ve both been killed.
Press the Face Buttons in each of the small alcoves. The teleporter doesn’t work so drop back into the pit and take the lift up again.
This time head to the south and east. You’ll come to a room where you’ll need to press a series of Buttons to lift up walkways to the next platform. Eventually you’ll make it to the Exit.