Doom2.wad required. GZDoom included. Because the sanest place is behind a Trigger. The mod includes 15 levels and some Doom 3 weapons ported into Doom, as well as the hud and some brightmaps. It also includes an expansion with another 11 levels made with Oblige level maker.
Now the mod got updated with better weapon responsiveness, tweaked campaign with more pickups, updated gzdoom, and a brand new expansion among other things...