Mario & Sonic at the London 2012 Olympic Games

Mario is invited to Peach's castle, but when he arrives Peach is nowhere to be seen. He soon learns from Toad that Bowser has once again kidnapped her. The Koopa King has also put a spell on her castle, imprisoning her subjects. So it is up to Mario to break the spell and rescue Peach.

The gameplay involves strategy and action as players control their chosen character, switching between them at designated checkpoints to perform different events such as sprinting, wrestling, or rowing. Players can collect medals by winning events, with the ultimate goal of becoming the champion of the Olympic Games.