My problem with Mario in USF isn't so much the attractions; it will definately address some major issues with USF. My bigger complaint is that it just feels... out of place? USF is filled with mostly urban environments, and the biggest stray from that is Diagon Alley, which is within the city of London, an urban environment. IOA meanwhile is mostly filled with more fantastical fantasy worlds, with the biggest stray being MSHI, which is very cartoony with super heroes all over. So having a large fantasy environment in USF just feels... out of theme, I guess.