Kill an enemy while he is on the side of the stairs. The enemy will die, but will be floating on the side of the stairs. If you kill an enemy at the top of the steps, the enemy should dead but fall down the steps.
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.
Allow an enemy to kill you. Once you have a bloody face and you are on the ground, enable the "God mode" code. Your character will come alive again, but will not be able to change guns, move, or shoot.
Enter idbehold as a code. A list of words will appear at the top of the screen. It makes you invisible, can see in dark places, but does not make you invulnerable to enemy attacks or have other effects as it states.
Cheat codes cannot be used in nightmare mode. It is just like the regular game, except the monsters are stronger and harder to kill. Enemies will keep appearing non-stop on each level -- you have to try and get to the end before more appear.
Listen for weird sounds, like somebody breathing very hard during the game. Those sounds are the brown monsters that throw fireballs. When the sounds stop, that means you have killed them all. However, there still may be normal enemies with guns and shotguns or pig monsters.
The snorting sounds in the game are coming from the pigs. Once the sounds stop, that means you have killed all the pigs.
In this hint&tip text, I will suggest the best weapon/way to kill every monster in the game.
Imp: Use a shotgun for this powerless monster. When using a pistol shoot it in the center,because it's easier to kill in that way [and it saves ammunition]. When you use the super-shotgun be careful, considering that if you miss a shot you will have spent 3 bullets.
Lost soul: For this monster use a fast weapon. Recommended weapon is the plasma-gun. But its cells are precious so use a chaingun when they came in large groups. When they come in smaller groups or they are in tight corners use the chainsaw.
Zombieman: Use a pistol. Pretty weak enemy.
ShotGun Guy: They could do a considerable amount of damage if the player underestimate them. Use the chaingun if they are too many, or use a shotgun while combined with hiding+strafing while reloading.
Chaingun Guy: This guy can wipe out your health, so be careful. A well balanced shot with the shotgun is capable of whipping this monster. Otherwise, use a chaingun. If you want and trust your aiming, use the super shotgun but the longer reloading time is critical, due to chaingun's speed.
Demon/Spectre: The best way to fight a Demon/Spectre is the chainsaw. If you encounter many of these, try to fight one at the time, and it would be a piece of cake. Optional: A shot with super shotgun will perish it quickly.
Cacodemon: A fat monster, so it's an easy target. Don't go near it though. The rocket launcher is a good way to fight that fat baby. The super shotgun is very good too.
Baron of hell: Very high stamina. But it's very slow. Use your plasma gun in tight corners, or rocket launcher.
Hell knight: A weaker Baron of Hell. Use your super shotgun. A couple of shots will dispatch it.
Revenant: If it's only one or even two, you can use super shotgun alongside with hiding/running. Use stronger weapons if they are large groups.
Pain Elemental: Quickly use chaingun or your plasma gun , in order to eliminate them before spawning lost souls.
Mancubus: A large target, but a strong one. Use the rocket launcher or the plasma gun.
Arachnotron: A dangerous enemy. Use your chaingun in order to render it still without firing dangerous cell blasts. Use rocket launcher for large groups.
Arch-Vile: When you see it immediately kill it because he can revive other monsters. Use your plasma gun. This way he won't be able to react.
Cyberdemon: Rocket launcher combined with cyclestrafing is the best way to defeat him.
Spider Mastermind: Use plasma gun, and you will own her easily. You can use BFG if you want to, but you must run & hide while it's reloading.
- When a Revenants fires his projectiles, be sure not to stand still. If you do then his rockets will lock on you
and it will be difficult to dodge them.
- Pain elemental normally generates Lost Souls. But if there are 20+ Lost Souls in a level then the Pain Elemental won't generate other Lost souls.
- Defeating Cyberdemon with the rocket launcher is easier, because if you use plasma gun the constant cell fire rate will block your view, and you won't be able to dodge his rockets.