Travel through 18 levels of the planes of chaos with your demon as you receive orders from your overlord on what your next objective is. Battle a variety of underling monsters as well as Demons nearly identical to yourself. Along the way you will gain new armors and spells, as well as experience. Use your experience to upgrade your demon's stats or your weapon's power. In the end use your abilities to conquer enemy bosses and complete puzzles to do your master's bidding.
In each level you will be given a task. This requires the construction of a dark altar, which stores your magic abilities and revives you when killed. Objectives will vary from killing other demons to solving puzzles. Slaying a demon of your class or higher requires you to out think them, protecting your shrine while trying to destroy theirs.