That stage would actually get me way more hyped than the character himself. Never played a Professor Layton game before don't plan on to as it doesn't interest me. But the stage you described sounds amazing.
Also I agree with the guy above if this is true. There are still quite a few more Nintendo characters that could be added but have been overlooked like say....King K.Rool (no a mii fighter costume doesn't count), Dixie Kong, Krystal, Wolf, Inkling, Captain Toad, Sylux, Anthony Higgs, Medusa, Bandana Dee, Impa, Chorus Kids, Cranky Kong, Isa & Kaichi, Chibi-Robo, Issac, Captain Syrup. Those are just the first parties off the top of my head. You could also add more Fire Emblem characters, Pokemon, someone from Advance Wars, Warioware character. I mean there's still quite a few more Nintendo characters I wouldn't mind seeing added.