This game is set in what appears to be an alternate version of the Earth. A race of demi-humans has emerged, threatening the existence of humanity. The 15th human Emperor, named Sigmatoro J. Salzstein, calls Duke Erich B. Zweiss, and explains to him the mission: recover ancient crystals from the demi-humans, which alone can save humanity. But the Duke should be careful: who knows what challenges await for him among the demi-humans, outside of the safe walls of the capital city Berlin?.. Crystal Quest is a puzzle game with adventure elements - the Duke's top-down movement and the ability to access different locations to tackle different puzzles. The locations are marked on the world map as towers and caves; in each one of them, a sexy demi-human will offer a challenge to the good Duke.