The nitty gritty:
Big Singleplayer map set in Hell using 99,9 % vanilla assets (except the sky and a hanging victim texture)
You'll need GzDoom and doom2.wad (replaces Map01)
Features custom R667 monsters
Jumping / crouching disabled
Mouselook yes please
Best played with the following companion WADs: Smooth Doom, Highressounds, Fuzzball's Wibbly palette or Playpal plus, Tilt+
Download
Now on Idgames
Screenshots: