The player controls the actions of Theseus, Athenian prince of Ancient Greece, as he wanders through a randomly-generated (under user parameters) 3-D labyrinth in search of the horrible Minotaur, a monster half-man, half-bull, in order to slay the unnatural creature. Maze obstacles can include secret doors and "mirror maze" portions, as well as numerous monsters (snakes, specifically, are so common an opponent a specific key is dedicated to dealing with them!) The player begins with nothing but their fists, which suffice to vanquish weaker denizens of the maze, but stronger weapons are required to overcome the Minotaur. (Triumph is only achieved after the monster is both killed AND the player departs the maze from their original entry point -- though the maze can be exited at that location at any time, whether the Minotaur still lives or no.)
The game is 3-D not only in that the player navigates the maze from a 1st-person perspective, but also in that navigating the maze will involve ascending and descending through holes in the floors and ceilings.