Martian Buddy Cabinet:
Before the Alpha Labs, look for a locked cabinet called "FREE STUFF" by martianbuddies. Enter 0508 as the code, and don't worry if it beeps when you enter "0". Opening the cabinet will give you some ammo, armor and a chaingun.

Cheat Console:

To enter the cheats below, you must bring up the console by pressing CTRL + ALT + ~ (Press it again to hide the console).

God Mode: god

All Weapons, Full Health, Full Armor: give all

Walk through walls: noclip

Saves a demo game to an .AVI movie file: aviDemo

Game Benchmark: benchmark

Skip to last level: doomhell

Freeze all on screen: freeze

Graphics card information: gfxinfo

Invisibility to most enemies: notarget

Show FPS: com_drawfps 1

Load the 95 version of Doom: give doom95

Acquire all keys: give keys

Your game status: status

Quit or Exit: quit

Weapons:

Machinegun: give weapon_machinegun

Shotgun: give weapon_shotgun

Plasmagun: give weapon_plasmagun

BFG: give weapon_bfg

Chainsaw: give weapon_chainsaw

Rocket Launcher: give weapon_rocketlauncher

Monster Spawning

Flaming Zombie: monster_zombie_bernie

Chainsaw Zombie: monster_zombie_sawyer

Z-sec Zombie with machine gun: monster_zombie_zsec_machinegun

Z-sec Zombie with pistol: monster_zombie_zsec_pistol

Z-sec Zombie with shield: monster_zombie_zsec_shield

Z-sec Zombie with shotgun: monster_zombie_zsec_shotgun

Commando Zombie: monster_zombie_commando

Commando Zombie with Chaingun: monster_zombie_commando_cgun

Fat Zombie: monster_zombie_fat2

Fat Zombie with wrench: monster_zombie_fat_wrench

Bald Zombie: monster_zombie_maint_bald

Zombie with no jaw: monster_zombie_maint_nojaw

Zombie with Wrench: monster_zombie_maint_wrench

Skinny Zombie: monster_zombie_maint_skinny

Zombie: monster_zombie_maint

Zombie: monster_zombie_maint2

Zombie wth Flashlight: monster_zombie_ maint_flashlight

Headless Zombie: monster_zombie_suit_neckstump

Zombie: monster_zombie_suit_bloodymouth

Skinny Zombie: monster_zombie_suit_skinny

Zombie in Labcoat: monster_zombie_labcoat

Zombie Missing Limb: monster_zombie_limb

Zombie: monster_zombie_skinny

Zombie with a pipe: monster_zombie_pipe

Zombie in T-shirt: monster_zombie_tshirt_bald

Zombie: monster_zombie_tshirt_blown

Zombie in Jumpsuit: monster_zombie_jumpsuit

Zombie Eating: monster_zombie_jumpsuit_eating

Archvile: monster_demon_archvile

Cherub: monster_demon_cherub

Hellknight: monster_demon_hellknight

Imp: monster_demon_imp

Maggot: monster_demon_maggot

Mancubus: monster_demon_mancubus

Pinky: monster_demon_pinky

Revenant: monster_demon_revenant

Tick: monster_demon_tick

Trite: monster_demon_trite

Wraith: monster_demon_wraith

Cyberdemon: monster_boss_cyberdemon

Gaurdian: monster_boss_guardian

Guardian’s Seeker: monster_boss_guardian_seeker

Sabaoth: monster_boss_sabaoth

Vagary: monster_boss_Vagary

Level Jumping:

Mars City 1: marscity1.map

Mars City Underground: mcunderground.map

Mars City 2: marscity2.map

Administration: admin.map

Alpha Labs Sector 1: alpha1.map

Alpha Labs Sector 2: alpha2.map

Alpha Labs Sector 3: alpha3.map

Alpha Labs Sector 4: alpha4.map

EnPro Plant: enpro.map

Communications Transfer: commout.map

Communications: communications.map

Monorail Skybridge: recycling1.map

Recycling Sector 2: recycling2.map

Monorail: monorail.map

Delta Labs Level 1: delta1.map

Delta Labs Level 2A: delta2a.map

Delta Labs Level 2B: delta2b.map

Delta Labs Level 3: delta3.map

Delta Labs Level 4: delta4.map

Hell: hell.map

Delta Complex: delta5.map

CPU Complex: cpu1.map

Central Processing: cpuboss.map

Site 3: site3.map

Caverns Area 1: caverns1.map

Caverns Area 2: caverns2.map

Primary Excavation: hellhole.map