Even MORE details for New Super Mario Bros U!

• - Big Island included
• - Torpedo Teds, Koopalings, Monty Moles all return
• - Morton Jr. wields a giant hammer that can shape the platforms around you
• - King Koopa’s personal airship will dive in for a battle
• - Bowser Jr. is prone to ambushing you at random
• - one fight with him takes place underwater with a Clown Submarine that is constantly launching torpedoes
• - you have to guide the torpedoes back towards Bowser Jr.
• - Challenge Mode levels offer tough challenges set in very simple level design
• - challenge example: dodging fireballs thrown by two Fire Bros
• - dodge for over 40 seconds to claim the best prize
• - complete more objectives to unlock more in menus separated by broad type
• - types include Boost Mode, coin collecting, gathering 1-Ups or one simply called
  • Special example: get Monty to the finish by putting him on a raft, where he will constantly charge at you. Avoid him killing you or you killing him
• - he’ll blindly scamper right off that raft
• - there are other enemies that board the raft
• - raft stops moving if more than 2 characters are on it
• - more challenge examples:
  • Make it through a ‘Big Island’ level without killing a single creature
  • make it through a stage without touching the ground
  • use a single turtle shell to score a certain amount of extra lives
• - Coin Battle modes come from single player
• - customize the level with coin placement
• - craft coin for you and your friends

Source: Thanks GoNintendo!