Controls:
- Movement
- Activate and Deactivate Autorun
- Aim
- Shoot
- Use/Activate buttons
/
- Cycle weapons
- Pause
As DOOM 64 is a classic FPS game, there is no vertical aiming. You can only aim from left to right. The game handles that for you. If you aim below an enemy, it will shoot upwards at them.
You will have the maximum possible starting health and all weapons in your possession on basically all levels, so combat won't be too difficult. The trick to combat is to always be on the move, strafing at all times as you fight.
The red weapon which will be at the end of your weapon cycle is the Unmaker. This is the only DOOM game that it has ever been in and it is easily the best weapon in the game. It becomes better as you gain demon keys (this mechanic only affects you on one level using this walkthrough though).
On the main menu, press to start. Click options and then password. Enter the code W83M 7H20 BDYO N9VB.
As soon as you spawn, click in the left stick () to activate AutoRun. Then, use to cycle weapons until you have the red weapon (the Unmaker) equipped which is the best gun in the game. Grab the orb to the front-right of you and run through the door opening it with .
To the left, right, and center of the room, you will can find three colored pillars that close the doors where enemies spawn. Run up to each and click on them for them to sink into the ground (you may have to run around a little to get the enemies to spawn).
Shoot all of the spawned enemies and stairs will rise in the center as the final boss of the game appears. Run right up to the boss and just hold in the shoot button . It should easily die before you do.
Upon beating it, you will unlock:
Go back to the password screen (it is accessible via the pause menu and selecting options). Clear out the old code using 
, then enter the code RY48 9BFY 6?JM KBK?.
This will immediately spawn you in one of the 'Fun' levels. Run straight ahead and grab the RPG and one of the orbs. Strafe around the room firing at the enemies above you while focusing on them one at a time. You can find rocket ammo in all of the corners next to the red orbs. Each enemy takes three hits to kill. Once you finish off the last one, a yellow orb will appear in the center before the arena shifts. Pick it up as a new enemy spawns. Strafe back and forth, dodging its missiles as you keep shooting it. It will take a lot of shots to kill but will eventually go down. The mission doesn't end upon killing it, but for doing so you'll unlock:
Next, a bunch of fat fireball shooting enemies will spawn as well as more ammo and a couple medikits around the outside of the arena. Keep strafing, grabbing health and ammo as needed, until you finish them all off to complete the level. Do not exit out to the main menu because it will put you right into the next mission you'll want to play. For beating a 'Fun' level, you'll unlock:
You'll spawn in the first level. Drop down and pick up the shotgun, killing the two enemies that run into the room. Shoot the explosive barrel on your left. We will be blowing up all of these barrels to get to a secret level. Leave the room and grab a medikit on the immediate right if you're low health from the 'Fun' level. Then, head down the hallway going into the next room on your left. Kill the enemy in the room and shoot the barrel in the right corner.
Leave the room and turn left. Follow the hallway until you reach a wall with a down-pointing arrow on it. Go up to it and click to lower an elevator. Step onto it and wait for it to rise. Turn around and you should see a barrel on the right to shoot. Turn back around and go straight through the path, killing anything in your way. In the first alcove on the left, you should see a blue keycard. Walk over it to pick it up. Now, continue to the end of the pathway that you were following. Follow it to the left at the end and make the next left as well. The first wall panel on the left holds a secret area behind it, so walk up to it and click . The wall should lift up, revealing armor and another barrel to shoot. Do so. Picking up the armor will award you the following achievement for finding a secret area:
Go back to the elevator and fall down. You can now open the first (blue) door on your left. As you open it, an enemy and barrel will be directly in front of you to shoot.
Go up the stairs on the right and turn around. You should see a little raised alcove in the pillar behind you with a button in it. We will be coming back to this for the second to last barrel, so remember where it is. Turn right and head down the hallway and look left once you reach the dead end. Activate the button with to lower the wall directly behind you (and releasing some demons to kill). Shoot the barrel on the right side of the room, then click the button on the far wall. Head back to the top of the steps from earlier and there will be a new area to go into on the left. Go through and turn left. Enter the alcove on the left and the floor will drop, revealing another barrel to shoot. Shoot it and wait for the platform to raise you back up. Follow the path to the left and clear out all the demons in the next room. Enter the other door in that room and kill the final enemy, but do not exit the level. Directly to your left in the exit room will be another barrel to shoot. Do so.
Now, go back to that secret alcove from earlier. Line up with it and run forward, going up the little step to run right over the gap into it. Activate it with and back out to see an opened area in the far-right corner of the room. Run into it and shoot the barrel. Follow the path and walk into the red light to be teleported back to the start. Turn around and open the door behind you. On the left side floor, you will notice a blood splatter at the foot of the wall. That wall panel will shortly open up after shooting the final barrel so be ready to run into it. Go back out the door and shoot the final barrel on your right, then run back and enter the hole in that wall. The screen will fade to red as you unlock:
Go back to the password screen. Clear out the old code and enter: YWW4 7HVD BCLG RKVB.
You will have everything in the game, but this will be on the hardest difficulty so be more careful about getting hit. If you die at any point, just pause and go to the password screen again. It should be filled out except for the final B, so just enter that to restart the level with all your gear.
Activate the demon button directly in front of you to open all the doors and swap to the red gun again. Drop through one of the doors and start killing. On one side of the map, there should be a big lava wall with two alcoves down below. In the right alcove, there will be a green glowing radiation symbol. Drop into that alcove and grab it to gain a Radiation Shield. Then, run over the lava into the next alcove. Turn right at the crossroad where the path splits and enter the blue teleporter.
Follow the next path until you reach the ledge with a Mancubus (fat fireball demon) that may or may not be dead (kill it if not). Walk up to the ledge and look right to see another ledge with another possibly dead mancubus and a demon pillar to activate. Run off and try to land on this ledge. If you miss, you will need to go back through the blue teleporter from earlier. Click on the pillar and go back through the blue teleporter again. There will now be a hole in the wall at the end of the path. Go through it and activate the next pillar. The wall will open to your left to let you out and two Cyberdemons (the really tanky rocket demons) will spawn over by the lava wall. You need to dodge, duck, dip, dive, and dodge your way through the fight, killing them in any way possible. Mainly just keep your distance to be able to dodge their slow-moving, powerful missiles. Ammo can also be an issue in this part. If you run out, switch to the rocket launcher as your next best bet. This is the hardest fight for the completion. When the second one dies, you will have beaten the level and unlocked:
Now, go to the password screen and enter the code ?QDM 7HYC BB4X FJVB.
Pause and select Features. Do not use anything but the warp option as the rest disable achievements. Go all the way right to the second to last warp option 'Final Judgement' and click to be warped to that stage.
Run around the starting room and pick up all the weapons/orbs/whatever else. Among them to pick up will be the Unmaker and the BFG9000. By picking each of them up, you will unlock:
Then, go through the red teleporter and activate the pillar that appears in front of you. Run directly straight to see three colored pillars. We will need to pick up three matching, glowing demon keys to activate them. Turn right and hug the left wall until you reach a yellow orb and two doors. Open the left door and follow the path until you see the blue demon key to pick up. Do so.
Drop off the ledge to the left and go through the other door. Enter the teleporter at the top of the stairs. Follow the path around to another red teleporter and enter it. Step out of the teleporter, then go back ito it to teleport right in front of the yellow demon key. Pick it up. Go back through the teleporter again and hug the right wall until you reach a door. Go through it it, go up the stairs, and enter the teleporter. Follow this new area all the way to the end past the mancubi and open the door. Turn right and slaughter your way down the path. Grab the purple demon key.
Head back to the colored pillars and activate all three. Then, activate the other pillar in front of you. Turn around and run to the other end of the map to see the boss. Murder the hell out of it with the Unmaker to finish the level and unlock:
For the final achievement, we will need to collect all three of those demon keys again, but in the main campaign. We only need to actually grab one however.
Go to the password screen again and enter the code V87L 7C28 BDT1 59VB.
Swap to the Unmaker like always and go through one of the two doors. Go around the back and grab the blue skull key. Head back to where you spawned and open the blue door that was behind you. Go up to the second panel on the right (the one that looks different) and press on it. This will drop down some stairs to your left, allowing you to continue.
There will be a demon button to click on either side of the blue orb gate in front of you. Go up to the one on the left and activate it. Then, activate the button that appears behind it to lower the walls next to the blue orb. Head through one of the doors hugging the middle pillar and you will see a button on the backside of it. Activate it.
Turn around and head up the left staircase. Turn right at the top and turn right again into the wood-floored area to see another button. Click it. Keep looking straight at it and take a couple steps to the left until you line up with the wall on the far side of the open room. A button will appear here to shoot. Back up and look to the left. You will see a square hole in the wall of this wood-floored area. That pillar will also have a button to shoot after shooting the first one. Face back to the first button and back out of the room. Run forward and shoot the button as it appears, then quickly turn left and shoot the second button through the square hole. If you successfully did it, the pillar in the middle of the open room will lower. If it doesn't, try to do the shooting buttons again until it drops.
Drop down into the open room and grab the purple demon key to unlock: