• The Terraformer: CB92 NBPL SYL? JO27
• Main Engineering: BXYH ?G41 6Z4J PJ?Z
• Holding Area: CYCC MGPK X47G TS2B
• Tech Center: CF3? PG6D S12Z PFKB
• Alpha Quadrant: BXRO TH1F 52GG 7W?B
• Research Lab: BBXW HLGS XB8F 4RKB
• Final Outpost: FVV9 FL55 QGFV DWJB
• Even Simpler: FFLB MQ6C VV1C PF1B

Doom 64 has a hidden cheat menu within the game, and here is how to access it....

In order to reach it, you do NOT enter a key sequence as with most games, but rather, you must first discover Level 32, then survive it, and collect all three keys in it. Getting all three keys is NOT necessary to exit the level, but is needed to gain access to the Cheat Menu.

To get the secret Cheat Menu, U must find the hidden Level, which is Level 32-Hectic

Here is how to get to Level 32-Hectic

• To reach Level 32-Hectic in Doom 64, you must start a new game. Go through Level 1-The Staging Area, and destroy ALL the barrels, except the one to the right of the start. There are a total of 10. Remember the secret areas, the room with the exit, and the alcove in the hallway leading to the exit. Be sure to collect the Soul Sphere and Combat Armor for a better chance at surviving later on.
• Once you've destroyed all of the level's barrels, take the teleporter that you can access from the secret area behind the Blue Door. When you reappear, destroy the barrel ahead of you on your right and enter the door behind you. A secret area will temporarily open on the left wall that leads to Level 32-Hectic.
• Now Remember, to access the Hidden Cheat Menu, U must get ALL THREE KEYS on Level 32, so here is how U go about doing that...
• At the beginning of Level 32-Hectic, enter the door to the right for the Red Key. Once you pick it up, you'll be dropped into a room with three Arachnotrons. Quickly go left or right to get the Rocket Launcher. Destroy the Arachnotrons and return to the door that leads to this room. Beware of the crushers that come down from the ceiling, search the wall to lower it and let it raise you back to the main room.
• Enter the door on the other side of the room to get the Blue Key. As soon as you get it, run back to the door you entered from. The ceiling will crush you if you stay in the alcove where you find the Blue Key. Four Hell Knights will appear and the door you came in from will be closed. Destroy them with your Rocket Launcher to be able to leave the room.
• Enter the door on the left side of the room, at the opposite wall is the Yellow Key. The floor rises in different parts of the room, and darts will fire from the faces in there. Try your best to avoid damage while getting the Yellow Key.
• Exit the room to return to the start. Directly across from you is a switch you will now be able to access. Having the keys, you can now remove the bars and press the switch to exit Level 32-Hectic.
• Once this is completed, you will gain access to the Features Cheat Menu in the Options. In that menu, you will find the following cheats...
• 1.Warp to Level-This is the ONLY way you can access Level 25-Cat and Mouse, Level 26-Hardcore, and Level 27-Playground Three secret levels in between Level 24 and 28.
• 2.Invulnerability-Turn God Mode ON/OFF using Button A or B.
• 3.Health-Use Button A or B to restore your health.
• 4.Weapons-Use Button A or B to get all weapons and full ammo for each.
• 5.Map Everything-Turn Map Everything ON/OFF using Button A or B.
• This is VERY HARD to do, beating stage 32 I mean, but if U succed and get all three keys, the cheat menu will appear.

This is 1 of the (i think) 3 secret boards! In each secret board there is a secret key! In this level the key is BLUE. Get the BLUE secret key (it will show u that u have it in ur map) and use it to help u on the last level (level 28)! On level 28 use each key on each colored stone! This will close up a 1 of the 3 portals! This will save u energy for the last boss!

This is another 1 of the 3 secret levels (i think). This level has the secret Purple key! This key is VERY tricky to get! I shouldnt tell u.....But i will :) Ok first enter this board and get the blue key. Then enter the blue key door and kill the demons. There is a secret wall u can push to the right of u, the wall is a different texture then the others. This lets down the stairs so u can keep on playing the board! Go next to the glowing face, wall, thing (doesnt matter which 1). This will let down a switch push the switch! (the one on ur right lets a bunch of imps out WATCH IT) (the one on ur left opens up some doors WATCH OUT theres knights in there) Ok after pushing each switch and killing everyone, go into the place where the knights were. Here you should see the Glowing Purple (secret) key! Push the switch that ull find! This will release a couple of imps and 2 Arachnotrons. Go up the stairs and kill em! Ok up there u will see 2 switches! One of em will open 2 more Arachnotrons and imps! The other will open a door that u dont have to worry about until later! If u goto Options and turn down the Music it will help a real lot at this time! Go to the switch that opened the door that u dont have to worry about! (the one up where the Arachnotrons were! When u step inside the wood space u SHOULD hear u thing drop then close! This is not a wall that drops and u have to run into it! Its another switch that u have to shot! When you hear the thing drop dont go anywhere! Look to ur right where u should see a little switch on the far wall! Shot this switch then, Turn to ur left and look out the little window. You'll see another little switch shot it and it will drop THE PURPLE KEY!!!! Then beat the board!

After you die, notice that you fall but the screen won't go "blood red" until you press a button. If you wait and don't press anything, the messages at the top will say stuff like "look at those demon feet!" It gets pretty funny if you keep waiting.