[3] The ninth main installment in the Mario Party series, it was announced at E3 2011[4][5] and released in Europe, North America, and Australia in March 2012, followed by Japan a month later.

Mario Party 9 includes seven game boards, twelve playable characters, and more than eighty minigames.

The game received mixed reviews from critics, with praise for its gameplay, graphics, multiplayer, minigames, and content, considering it an improvement on its predecessor.

[6][7] The number of spaces the player moves is determined by a roll of the dice block found within the game.

There are 81 minigames in Mario Party 9, divided into five categories: Free-for-all, 1-vs.-Rivals, Bowser Jr., Boss Battle, and Extra.

Additionally, the game provides seven boards: Toad Road, Bob-omb Factory, Boo's Horror Castle, Blooper Beach, Magma Mine, Bowser Station, and DK's Jungle Ruins.

The game's story mode begins with the player selecting one of the ten starting playable characters.

The player character travels through all six courses to recover the Mini Stars, fighting off two henchmen selected by Bowser.

Rescued by (the character that the player chose), the Mini Stars were free to glitter in the night sky forever."

[31] As of December 31, 2020, worldwide sales had reached 3.11 million units, making Mario Party 9 the 26th best-selling game for the Wii.