2-on-2 Tag, Pipe Style!
From the Super Mario Wiki
2-on-2 Tag, Pipe-Style! is a 4-player minigame in Mario & Sonic at the London 2012 Olympic Games (Wii).
Players play tag on the Vacant Lot map with a gates that block the path and color Warp Pipes that take the player to the other side of the map. The team the player is on is randomized at the beginning. If an evader is tagged, they are removed from the map and (if they are a human player) watch the other player. Either team can use items to their advantage. The game ends when either the time is up or both evaders are tagged.
Wii Remote held sideways
Wii Remote and Nunchuk
Objective: Tag everyone or keep at least one free!