Outbreak

Not that hard to do. No, the tutorial does not count. Try it on hard first.

Nightmares>Captive

-passwords are 35845 + 135
-take your time put lots of distance between enemies, reload off screen and use barricades
-You get the silver key from the killing the second spider at the spot where you start
-after getting the shotgun ammo, you will be swarmed by 5 zombies
-in the furnace room, you have to trigger a swarm by talking to the security guard
-in the garage, you will have to trigger a swarm by talking the other security guard
-heading to the exit, you will be ambushed by 5 zombies
-you have to kill the tyrant to exit

...watch out for laptops

I found it the easiest clear (nightmare).

- The punch is the most OP weapon in the game, insane knockback.
- At the beginning use the npc groups to kill everything, protect them with your bare hands, don't waste a single bullet. Taunt enemies and guide them to the nearest npc group.
- Code is 882255
- Once you need to go to laboratory, avoiding any unnecessary enemies and start using your rifle, grab the shotgun.
- Go straight to laboratory objective, kill the 4 hands thingy and back to the lobby.
- Go straight to the morgue, kill the tyrant, grab the key.
- Go back to the main lobby (you should face no enemies in the way back) and the upper door, use key.
- Go straight until you need to scape, you will be in a room with a tyrant, a 4 hands thingy and the meat ball, run to the upper left, kill the 4 hamds thingy and done.