I'm kinda disappointed with the boards themselves. Most of them are pretty short and feature nothing interesting.
"Perilous Palace Path" is very luck-based with the items, and some of them are kinda cheap, like the "Chaos Kamek" item. "Banzai Bill's Mad Mountain", "Rocket Road" and "Kamek's Carpet Ride" are all ridiculously short, to the point where a game in Banzai Bill's Mad Mountain is over in less than ten minutes. Kamek's board is also pretty bland, and even though it is split into two "sections", it's still a small board. At least the card gimmick allows you slightly more control over the amount of spaces you move. The one board I really liked was "Star-Crossed Skyway", since it is one of the bigger boards and has more to it than the others. I haven't played the "Shy Guy's Shuffle City" board.
As for Rosalina's appearance in Rocket Road, it seems they included her there just for the sake of including her, since all she does is clap for the character who wins the board. I was expecting a much bigger role for her than just standing there, watching the characters.