Avalon Code (Japan: メルルのアトリエ～不思議な本の扉～) is a role-playing game for the Nintendo DS handheld gaming console. Developed by Matrix Software and published by Marvelous Entertainment, the game was released in Japan in March 2009. In Avalon Code, the player takes on the role of a young protagonist who is tasked with the mission of saving the world by using the mysterious Book of Prophecy. The Book of Prophecy is a magical artifact that can be used to rewrite the fate of the world by altering its pages. The player must explore the world of Avalon and fight monsters in order to collect different items that can be used to customize the Book of Prophecy and change the world's fate. The game features a unique battle system based on a grid system and a variety of customization options for the Book of Prophecy. Avalon Code also features a variety of mini-games and puzzle elements. The game's visuals are vibrant and colorful, and the soundtrack is composed by the renowned composer Hitoshi Sakimoto. Avalon Code is a highly enjoyable and engaging role-playing game that offers a unique twist to the traditional RPG formula.