Paper Mario: The Thousand-Year Door (also known as Paper Mario RPG in Japan) is a 2004 role-playing video game developed by Intelligent Systems and published by Nintendo for the GameCube. The Thousand-Year Door is the second game in the Paper Mario series following Paper Mario, and is part of the larger Mario franchise. In the game, when Mario and Princess Peach get involved in the search for a mystic portal that holds great fortune, Peach is kidnapped by an alien group called the X-Nauts; Mario sets out to find the treasure and save the princess. The Thousand-Year Door borrows many gameplay elements from its predecessor, such as a drawing-based art style, and a turn-based battle system with an emphasis on timing moves correctly. For the majority of the game the player controls Mario, although Bowser and Princess Peach are playable at certain points. The game was announced at a 2003 Game Developers Conference and was released mid-July 2004 in Japan and late 2004 for the rest of the world. The game was praised by critics, generally lauded for the its engaging plot and gameplay. The Thousand-Year Door won the "Role Playing Game of the Year" award at the 2005 Interactive Achievement Awards, and is commonly called the best game in the series. The game was followed by Super Paper Mario, which released for the Wii in 2007.