The Doom Alphabet Game

Bloodfalls

Chocolate Doom

Doom Honorific Title

E1M1

Flashlight

Gibs.

Hectic (Doom 64)

Invurnul ability

Joe Pallai

Kotzugii

Linear levels

MBF (Marine's Best Friend)

Nuclear plant (E1M2)

Gez said:

Kotzugii

:)

OBLIGE

(from the OP's list)

PWAD

Quarantine (d2twid map08)

Risen3D

Spectre

TC (Total Conversion)

Unto the cruel (E4M8)

Vae Victus (Wad series by Ditto head).

Water

That is too broad. Like alot of the other words you mention.

XWadEd

Yesterday's Nightmare

Think that was mentioned Avoozl, could always have Yesterday's Brownies which is an old DM level.

Zenimax

Adrian Carmark

Bethesda

COMPET-N

I see ??? next to "big badasses" in the OP. Allow me to explain. First, play some nice background music to set the mood (click on Youtube vid), then read the quote below.

Once you beat the big badasses and clean out the moon base you're supposed to win, aren't you? Aren't you? Where's your fat reward and ticket home? What the hell is this? It's not supposed to end this way! It stinks like rotten meat, but looks like the lost Deimos base. Looks like you’re stuck on the shores of Hell. The only way out is through.