The concept is simple, thrust into a sudden black-out and the ever approaching presence of the Screecher, Creeper and Stalker; you must take your lantern and make your way to the exit, before your soul falls victim to the dreaded monsters. You are utterly defenseless, relying only on the light of your lantern to keep you safe. Keep your fuel in check and your breath calm, those are the only things to keep you alive.
It's like Amnesia and Slender meets Doom, its hard to describe how this feels, but picture those games but more encounters, more darkness and generally difficult especially if you play with the regular monsters activated. If you want Doom to be a whole new experience, atmospheric and scary, then this is the mod for you.