New Super Mario Bros. Wii is a 2009 side-scrolling platform video game developed and published by Nintendo for the Wii video game console. The game was released worldwide in November 2009, and in Japan the following month. It is the first Super Mario game to feature simultaneous multiplayer gameplay, and the first title to include Nintendo's new "Super Guide" feature. To highlight the uniqueness of the title, Nintendo chose to use a red keep case instead of the traditional white. The game is also the first Mario sidescroller to have up to four player multiplayer.