 Nintendo first revealed The Thousand @-@ Year Door at the Game Developers Conference of 2003 . Before its release , the game was confirmed to be a direct sequel to the N64 game Paper Mario and was known tentatively as Mario Story 2 in Japan and Paper Mario 2 in North America . A preview of the game was available at E3 2004 ; it included Hooktail Castle and a Bowser bonus level as playable stages . The game was released on October 11 , 2004 , in North America . 
