Dark Castle is a platform game that was released for the CD-i in 1991, originally developed for the Macintosh in 1986. Players control a character named Duncan who must navigate through a dark, eerie castle filled with puzzles, traps, and enemies, in an attempt to defeat the evil Black Knight. The game is known for its challenging gameplay, distinctive visual style, and haunting atmosphere. As an early platformer, it stands out with its mix of puzzle-solving and action, setting the stage for many games that followed in the genre.