Type t in the map to enter talk mode, then hold ALT and type "iddt" multiple times. This will reveal the entire map. Repeat the code to reveal all items. Repeating the code again will return the map to normal.
Note: This procedure requires editing a game file; creating a backup copy of the file before proceeding is recommended. Enter the "/doom 95" folder and find the "doom1.wad" file. Make two copies of this file and rename one to "Doom2.wad" and the other to "doom3.wad". You now should have all episodes to the game.
The following is a list of enemies and a brief description:
ENEMY - DESCRIPTION Former Soldiers - They resemble your old friends, but now they just fire pistols at you. They drop clips for the chaingun and pistol when killed. Former Sergeants - Meaner and tougher. They carry shotguns and do more damage then soldiers. They drop shotguns when killed. Imp - This creature throws fireballs and takes more bullets to kill. Demon - Appear in most areas and can rip your head off if you are not careful. If you see more of them, use the chaingun. Cacodemon - These creatures are ugly and have one big mouth. If they see you, they will fire lightning balls from their mouth. Use your rockets. Mancubus - You have to use more then a chaingun to kill them. Use ammo with caution. Arachnotron - Fires plasma energy at you. Use your rifle. Spider Demon - The ultimate enemy. Has a super chaingun mounted on her body. Use your plasma rifle or rocket launcher.