The Castle Quest game follows the story of a hero who must rescue a princess from a dragon's castle. The dragon has cast a spell to make the land fall into eternal darkness, and it's up to the hero to break the curse and restore light to the world.
In gameplay, players take turns moving their units around a small chessboard, trying to reach the enemy king. When two pieces meet on the same square, they engage in a magical battle, with each unit receiving a random playing card that determines its attack or defense. Units can also cast spells to damage or heal surrounding squares and units.