Compact by the standards of the Galaxy adventures but still loaded with bountiful secrets, beneath the warm familiarity of 3D World lies one of the strangest Mario games in years - or at least one of the most random in its influences and its moment-to-moment indulgences. And that's a very, very good thing. The Wii U sees Nintendo's mascot racing into venerable middle age by going wonderfully loopy - by dialling up the energy, even if the end result is often absolutely insane. After all these years, who could blame him?