Castlevania II: Belmont's Revenge is an action platform game released for the Game Boy in 1991. It is the second Castlevania title for the Game Boy and serves as a sequel to the previous title, Castlevania: The Adventure. Belmont's Revenge is included in the fourth volume of the Konami GB Collection compilations.
Set fifteen years after the events of Castlevania: The Adventure, Dracula returns and kidnaps Christopher Belmont's son Soleiyu at his coming of age feast, and turns him into a demon. With Soleiyu's mystical powers, Dracula retakes human form and rebuilds his castle, forcing Christopher to confront Dracula once again to save his son and Transylvania.
Unlike the previous Game Boy title, sub-weapons in the form of holy water and axes are available in the game. There are four initial levels, each taking place in a separate castle with unique theme such as air, plant, earth, and crystal, and can be completed in any order. There are also very large trap rooms in the levels. The game also utilizes a password system.