IF Quake: This is Quake as a text adventure. I downloaded it and walked around a bit — it seems like a perfect re-creation, as closely as I can remember:
You find yourself in a room with three corridors, each leading to a slipgate. On either side of you are stone pyres, their flames flickering softly. Directly in front of you is a metal structure with the word QUAKE carved into it. The structure splits into three corridors, to the northwest, north and northeast respectively.
You can see a Text File here.
As you make your way into the north corridor, the phrase “THIS HALL SELECTS NORMAL SKILL” manifests itself in front of you. The effect is quite disconcerting. To the north is a pulsating, rectangular slipgate with the word “NORMAL” etched on each side. To your right and left are stone carvings of some sort of demon. The path you followed to get here lies behind you to the south.