You play Gordon Brown, and its down to you and your trusty axe to save the world from the dark creatures of the underworld.
Nick Griffin is an easy enemy to kill. Two Shotgun or Axe hits can kill it. The trick to killing it without a scratch is to circle-strafe it. It’s too slow to catch up with you, so you can fire away at it without it retaliating.
Hagues have extremely low HP, which means that you can kill them with two shotgun blasts or axe hits. Their shotguns are pretty weak, even without armor.
One or two Hagues will barely harm you, but a large group of them can inflict some good damage, especially if they fire at once. If you do encounter a large group, take out your Nailgun and kill them from a distance. Their shotguns are ineffective at medium or long range.
Alone and with other Camerons, a Cameron is easy to kill. Two Super Shotgun blasts can kill it. To avoid its projectiles, just strafe around it. If there’s a group of them, take out your Nailgun and wipe them out.
Alone, an Osborne is extremely easy to kill. Just gib it with an explosive weapon and go on your way. A group of Osbornes is much more dangerous, but can be handled the same way, just try to aim at the “center” Osborne so that the explosive hits and and gibs the other Osbornes around it.
Alone, a Johnson isn’t a real problem. Get close enough to it so that it tries to swing its chainsaw, then run back and take it out with the Super Shotgun. If you’re far enough that he can fire grenades at you, take him out with a Nailgun from a distance. It’s not worth eating a few grenades so that you can take him out with the Super Shotgun.
Alone, a Major is real pain to take out. Even though it takes around four Super Shotgun blasts to take it out, the Major is fast enough to attack you while you’re attacking and reloading the gun. Instead, take out the Super Nailgun and begin firing. He’ll stop often, allowing you to get far away so that his sword won’t reach you, and he’ll be killed before he can utilize his fireballs.
Alone, a Thatcher is a challenge to deal with. Its electric attack can take up to 30 life points, and it will hit unless you’re hiding behind a wall. Since it’s so large, if you’re within even a reasonably short distance it’ll try to use its melee attack on you, which can take of up to 40 life points in a single attack. Since the Thatcher takes half-damage from explosives, use your Super Nailgun and Lightning Gun against it. Both of these weapons will take out a Thatcher in no time. If you see the Thatcher starting to use its electric attack, run behind something, even if it’s a small pillar. If the Shamber can’t see you, the attack will miss you.
Alone, the Portillo is a pretty powerful monster. Its jumping attack is very fast and can inflict a good amount of damage. The best way to evade its jump attact is by constantly strafing so that it will miss you. Don’t try and get close to it, as its melee attacks will lunge it closer to you. Alternatively, get a corner or a low doorway between you and Portillo so that it will try to jump at you, but will hit the corner or the wall instead. After that, it can be safely taken out. Avoid using explosives against it in melee, as it frequently gets close to you via jumping before the missiles hit it, inflicting you with splash damage. The (Super) Nailgun is the best weapon to use against Portillos, as its accuracy allows you to keep a safe distance from them, yet allows you to inflict major damage.
Fighting tips from the Quake Wiki.