Altered Beast: Guardian of the Realms is a classic action-adventure game released exclusively on the Game Boy Advance in 2002. It serves as a sequel to the original Altered Beast game. Players take on the role of a shape-shifting hero tasked with defending the mythical realms. By collecting spirit balls, the protagonist can transform into various beast forms, each with its own special abilities, to combat the minions of evil. It's a game that combines elements of mythology with side-scrolling beat 'em up action, making it both nostalgia-inducing for fans of the series and a fresh experience for new players.