Everything about it, even the technical standpoint of it, the frequent high 60 fps even on handheld, it looks incredible.
Something which I was wrong about, all the promotional art, the case cover, the gameplay shows made it out like new donk city is the hub world of the game. It's so not lol I've been through 5 kingdoms and I haven't even seen it.
This game is more like sm64 except imagine instead of having a star select, all the stars were available on the level at once and whilst there is a direction to play each world in (the story directs you to key moons), you can go off and get stuff in any order. Some worlds are more streamlined so you'll go from one area to the next, and probably get the moons in the same order everytime whilst order worlds like the desert one is more open and you could end up doing it in any order.
The graphics are phenomenal, but i'm glad not at the expense of framerate which i'm really impressed with. The controls are fluid...the only thinking i'm concerned about is this is the type of game that once i've got everything, it's over. There's no running about doing extra quests and finding new things like final fantasy 15, once all the collectibles are gone then there's nothing more. But I guess even a huge sandbox game like ff15 you'd be done with eventually. I just don't want it to end xD