The following info comes from an IGN interview with Producer Yoshiaki Koizumi and Director Koichi Hayashida.
- when working on Super Mario 3D Land, they thought multiplayer would be great
- this didn't make the cut for the 3DS
- they felt the power of Wii U could help them achieve this
- is influenced by the eccentric and wild levels designs from the Galaxy
- won't comment on story yet