I'm half-way through the levels I think at the moment, going by the balloon's progress, and really enjoying it. It's basically everything I was expecting. It takes the great world design and collectible hunt of 64 and Sunshine, while also having elements seen in the following 3D Mario games. Even the motion control inclusion, something I've talked about in length on how much I don't like it, is done better here, being completely option and more usable on a far better controller if I really need it.
It's pretty great and what I've been wanting for awhile. Yooka-Laylee and A Hat in Time had good stuff in them, but were held back by basically being lower budget indie titles, whereas Odyssey has the potential to be one of my top favorite Mario game. Kinda crazy to get both this and BOTW this year and becoming my favorites of the series.
*EDIT*
Already posted my basic review in the 52 Games Challenge thread, so I'll just say that I think the game is fantastic, on the verge of perfect, if it just wasn't re-using boss fights. There are unique ones, at least 6 I think, but you fight the Broodals and Bowser twice and I hate when Mario games do that. Just toss in the Koopalings for mini-boss fodder if you have to, just do anything other than slightly harder versions of fights I had already done. Otherwise, I think it's my favorite Mario. Got so damn much to collect now, wearing a wonderful outfit that made me quite happy, though I won't spoil the surprise.