Shadow over Mystara is a sequel to Dungeons & Dragons: Tower of Doom. Two years have passed since the heroes defeated Arch Lich Deimos, but now a new threat has arisen - a powerful sorceress Synn who is plotting to conquer the Republic of Darokin.
Shadow over Mystara is a side-scrolling beat-'em-up with role-play elements that make it stand out from other similar games released at the time. The game is set in Dungeons & Dragons campaign setting of Mystara and features monsters, areas and playable characters typical to D&D adventures. There are six playable characters to choose from: Cleric, Dwarf, Elf, Fighter, Thief, and Mage - each with unique abilities, strengths and weaknesses. The characters can equip different gear and weapons, use special abilities. Magic-users have a wide range of magic spells. The characters are awarded with new spells and abilities as they gain experience. Many game mechanics are realized according to D&D rules, for example, the thief can detect trapped chests and cleric can turn undead. The game has branching paths and a variety of endings.
Shadow over Mystara features up to four-player cooperative play.