If you get a 100% completion, you'll unlock Mii versions of Mario and Luigi. Note that this is exclusive to the EU version of the game.
Nintendo's new line of NFC-powered toys, called amiibo, will unlock special costumes for players to wear in Mario Kart 8, according to the game's official site. As part of a forthcoming software ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results
Feedback