Devil Island, also known as Emo Dao (惡魔島), is an action role-playing bootleg game for the Game Boy Color developed by Vast Fame. It copies Konami's Japan-exclusive NES game, Getsu Fuuma Den, with its gameplay. The game's aesthetics are styled after the Castlevania franchise, also by Konami. Much like Castlevania, the player's default weapon is a whip, except it can be held down for rapid fire.
This run abuses the demo mode of the game to get all items and reach the end of the game early, which is why it is so short. See the author's comments for some explanations.