Someone pointed out in the YouTube comments that one of Mario's costumes is from a Japanese New 3DS commercial:
http://images.nintendolife.com/news...ng_kisekae_plate_covers/attachment/0/900x.jpg
http://images.nintendolife.com/news...ng_kisekae_plate_covers/attachment/0/900x.jpg
(Costume spoilers, not that big but just gonna play it safe)