I think sales-wise the way they chose was the worst one, I think both a Galaxy 3 or a Mario 64-type game would have sold more. Not in extreme amounts, but probably more. Needless to say though, 3D World hasn't stopped selling yet, and we should wait for Nintendo's figures this month (if they update this game).
I think a Galaxy 3 would suffer from a 'been there, done that' reception, but it would be considered a 'real' 3D Mario. 3D World lacks that perception, on top of it being viewed as 'just an upscaled 3DS game'. A 64-style game, of course a modern, innovative take on it, would be a refreshing change of pace for Mario because the last time they done the franchise that way was Sunshine on GameCube, which didn't really work out the way it should. It would probably also be the most welcomed style by the mainstream, with it being semi-open world and as such much grander in scope. The current N64 nostalgia in general would also help it.







