My review is from the "father of a toddler" perspective. For those of you who have a child on the younger side, and you still enjoy Mario, don't hesitate to buy this game! My son can sit and watch this as if it is a cartoon and remains entertained the entire time. Sometimes he will say "make Mario do this" and is excited when it happens on screen. As someone who is a bit older but still enjoys games, it is a treat to find a game that entertains my son while I play.

Good game, not perfect.

What I like:
I really enjoy finding all of the fun little easter eggs scattered everywhere and anywhere throughout the vast array of kingdoms Mario can explore.
The new mechanic of Mario throwing his cap and capturing enemies to gain their powers is a nice little addition to Mario. I am a big fan of Kirby, and it doesn't seem like we're going to get an open world Kirby game for Switch, at least not soon. So this is kind of a nice compromise. Mario with a just a hint of Kirby. Turning into a T-Rex is just as fun as the trailers made it look.
Although there isn't as much to be seen from your old favorites like the Shy Guys, Koopas, etc. I really enjoy some of the new NPC's. I especially like the skeleton heads (Dia de Los Muertos) type characters in Toastarena and the Robots of the Wooded Kingdom. Some of the great iconic moments of this game include these NPCs, like finding yourself in a secret room rocking out on your guitar with them.
The two player is really interesting. At first glance, having one player control Mario, and the other control Cappy seems like you'd have some much watered down gameplay, but that isn't necessarily the case. Cappy is able to move around freely as your player 2 and can jump and explore and even ground pound like Mario. To be honest, if anything, Mario feels a little crippled in the 2 player without being able to freely use Cappy. However, this is made up for somewhat by the fact that some new jumping possibilities exist when you play cooperatively with your player 2 controlling Cappy. It emphasizes that Cappy is a living being and an integral part of the story, but I still miss Luigi... I mean as a little brother it was demoralizing to have to play as Luigi...now little bros get to be a hat...

What I dislike:
Earlier, I applauded the plethora of Easter Eggs. They are a blessing and a curse. They are very different games, but Odyssey will continue to inevitably draw comparisons to Breath of the Wild. While the Easter Eggs in Breath of the Wild made the journey that much more exciting and full-bodied, the Easter Eggs in Odyssey seem like they ARE mostly the objective. The story line is fairly weak so far, so the game makers had to compensate for that by adding a seemingly endless number of collectibles. Every stage is formulaic. Bowser took whatever random wedding thing, you have to get it back...blah blah.
Aside from that, the power moons feel really inconsistent. You sometimes get them for just ground pounding a sand dune, but sometimes you have to spend a half hour and a dozen deaths swearing at your TV in order to obtain these glittery lunar prizes.
The motion controls are really annoying. I know lots of people have said it, but it needs to be mentioned. The game is mostly playable without getting too crazy with your motion controls, but more than a few times, I've found myself losing HP or even dying because I couldn't get Cappy to do what I wanted. There are very few ways in which they enhance gameplay, like shaking the controller upside down to climb faster...but that really just feels unnecessary. There are a lot of people who swear by the motion controls on other games like Splatoon 2, and I accept that. Just offer gameplay that is equally as robust without them. There are puzzles and secret areas that are essentially impossible without motion controls so the game's statement that motion controls aren't necessary is false.
Another gripe that I have is that there is an endless amount of new costumes and combinations to play with, but they are essentially just skins. All costumes do the same thing and do not affect game play in any way that I've seen so far. That's somewhat disappointing, and I think it's a missed opportunity to add some more depth to the gameplay.

Overall, I think the game is really solid, but not perfect. It has some of the innovative gameplay of Mario 64, some of the charm of Paper Mario, and a bit of a twist in the mechanics like Sunshine, but honestly, it doesn't do any of those things quite as well which is why I gave it 4 stars. Anybody rating the game lower than a 3 is probably a troll. Despite its shortcomings, it's still a really great solid game that will give you lots of hours of exciting gameplay.

Edit: having completed the game (current moon total 505), I can say this game is really a triumph for Mario. Nothing has changed from what I wrote above but some of the post game and final worlds really sold me. The game gets beautifully nostalgic at the end. You won't regret buying it.

Honestly this is my favorite console title to date. Very few games make me want to sit and play for hours on end. Even with Breath of the Wild, I haven't beaten it and can't get myself to play for extended periods of time.
But this game is glorious.
I'll leave this review spoiler free for the sake of those looking into purchasing this awesome title.
It took me about 4 days to beat the main story. This included getting 8 hours of sleep and a work/school schedule. But that was using all of my free time playing this fantastic game. And even after that, there is still a LOT to do after the main story, so I've been playing it still.
This is a console quality mario game. In my opinion it's the best 3d open-world mario title to date. Mario 64 will always have that nostaliga spot for me, but this is the new winner in my eyes. Not only because of the gameplay, but with the nature of the switch it's also a portable title. I played this while waiting at campus for a class to start. Almost was late to class because I lost track of time.
And the mechanics are great. Even after beating the main story, I find myself learning new advanced moves that make previously tall walls easy to get over.
The music is also good. Not all of it is super memorable, but there are several songs in there that I would pay to have downloaded on my phone.
I highly recommend anyone who is even remotely considering this game to pick it up. I wasn't even super excited to get it, but decided to give it a go and now it's my new gaming addiction.

While it may sound backhanded to say that this is the best Mario game since Galaxy, it's not intended as such. Odyssey is spectacular. I've been playing Mario games since the very beginning, so I like to think I know a thing or two about them. Super Mario Odyssey may well be the best 3D Mario game ever made, and it's in my personal top 3 Mario games of all time.

As you might've seen advertised, the big new feature is Mario's sentient hat companion Cappy, who lets him possess many of the denizens of the various kingdoms you visit in this adventure. While the highlight of many Super Mario games throughout the years has always been the various suits and power-ups players can get their hands on, being able to outright become many of the creatures you come across is a twist on that formula that lets players do all kinds of new and sometimes unexpected things.

While the game is - as expected - family friendly, it provides layers of challenges for players of all ages. Some of the (optional) tasks in the game are outright hair-tearing, for only the most skilled players, but that's part of what achievement is all about! However, while the game is designed to appeal to everyone, Nintendo took the time to add some extra nods to long-time fans, not only in the worlds and the critters/characters you happen across, but through setpieces and a spectacular mid-game musical number that old-timers like me have to appreciate.

If you have a Switch, get this game. If you don't have a Switch, get one, and then get this game. Whether you're a new Mario fan or an old one, this is the definitive 3D Super Mario experience.