Hard to take OP seriously when its written in such a childish way. OP Assumes that everyone shares his opinion and that 3D world is somehow a bad game.

In fact, as someone who has played and 100% BOTH games with 30-40hours invested in BOTH games, 3D world is the best platformer by far out of the 2. Odyssey isn't even that good of a platformer, it's more of a exploration collectathon game then a platformer which makes for one of the most disappointing 3D Mario platformers I've played. Also, Mario odyssey goes for quantity over quality with so many moons standing out in the open and most moons repeting themselves from kingdom to kingdom. (see below) I also feel that even when getting a moon in a challenging platforming level, it will not feel nearly as great because it's undermined by the hundreds of other moons that feel completely useless.

Also, no one seems to mention how Odyssey is incredibly tedious and repetitive if you actually begin to go for all the moons. In fact, a post from Neogaf summarised the overall game incredibly well: "SPOILERS"

"Can we please discuss how utterly repetitive the activities are in each kingdom to collect the moon?

1) Koopa race
2) Ground pound the underground bump
3) Trace the lines
4) Ground pound these 1000 random glowing and non-glowing spots
5) Red door where you find two moons
6) Scarecrow
7) Captain toad
8) Peach
9) "Feel" haptically where you should ground pound
10) Buy in the store
11) Match-3
12) Get the costume and find it behind the locked door
13) Find the art and moon is there
14) Impress the female goomba
15) Look at the sail with the telescope
16) Spin cappy on glowing object x
17) Open the treasure boxes in the correct order
18) Rocket
19) Dog
20) Collect 5 golden moons to unlock the actual moon
21) Bring the seed to the pot
22) Do some random challenge to a 100 (i.e. jumping rope, volleyball)
23) 8-bit

http://www.neogaf.com/forum/showpost.php?p=253010139&postcount=53

Another thing, the lack of memorable music. 3D world soundtrack is far superior in my opinion. After playing Mario odyssey for 40 hours, I remember maybe ONE song. That's it.

Anyways, in my opinion, Odyssey is kinda similar to how I felt with breath of the wild. Incredibly fun at first glance and fresh. But then, you quickly realise that it misses a lot of the things that made Zelda games,.. Zelda games. Same thing here for Mario.

EDIT: Also, before anyone attacks me for criticising  odyssey. I bought the game digitally while I already had my physical copy shipped from Amazon just to get to play it 12hours in advance which means I bought the game twice lol. 

I do not agree at all with this but this is your opinion. Odyssey's soundtrack is incredibly varied and very accurate with the intention it is destined to - whether it's to capture the overall feel or cultural appropriation of a kingdom. It feels... not so Mario-ey, but is more effective in its grandiloquence.

3D World themes are indeed catchier, but nowhere near as interesting musically as Odyssey. The only thing I could give the upper hand to is the narrower focus of World with its jazzy beats and disco-brass hooks. Of course, I believe it goes along the intention of 3D World and its rather less... grandiose adventure. Odyssey is wider, more ambitious, more engrossing, akin to what Galaxy was.

But no, I remember tons of songs from Odyssey as well as 3D World.

And that's fine. Obviously, I'm not going to stand here and argue about our opinions because theres no point in that really. It's just that the way the OP made it sound like Odyssey was the best thing ever created and 3D world was the worst PoS ever created rubbed me the wrong way.

I just wanted to show that OP shouldn't just assume that his opinion is fact and I'm surprised mods leave this bait title and OP up. Also, from looking at threads on neogaf and reddit (reading serious posts, not people who say stuff like "I hate the game but I never played it", I am far from being the only one that finds Odyssey underwhelming and repetitive to say the least. 

As I said, Odyssey is a solid 8hour experience. 3D world and other 3D Mario games are all solid 20-25hour experiences which is the big difference here... Again my opinion after 100% Odyssey and every other 3d Mario. 

But 3D Land lives on!

I really enjoyed my time with Odyssey and all, but it's seriously one of the easiest Mario games I've ever played and for that it loses points. 3D World's first couple worlds were pretty easy, but I'd have to say that game challenged me more. Odyssey looks great though!

They achieve a different objective. And they both stand their ground fairly at that.

For me a cornerstone of the "3D Mario" experience has always been the sense of joyous wonder that comes from discovering cool new things within playground-like stages, like being a kid again and climbing the play equipment to discover there's a fireman's pole or one of those giant spinning sets of blocks up there.

It's a feeling I never got from 3D World, but which 64, Galaxy 1/2, and Odyssey delivered in spades.

They are targetting different audiences, despite both being 3D Mario

A game built for 4 player co-op vs a single player game with a co-op mechanic

I really liked 3D World, especially playing multiplayer. Have yet to play Odyssey D:

SMO is the best Mario game I have ever played. And I have played every console Mario platformer as they were intended. (ie I had a NES with Mario 1,2,3 and played them before SMW or Allstars).

My current Mario top 5.

1. Odyssey
2. Super Mario World
3. Super Mario 64
4. Super Mario Galaxy
5. Super Mario 3

The reason SMO is number 1 is quite simple. It is evocating the same emotions I felt as a kid when I played Super Mario World despite the fact I am 25 years older now. In essence I did not think any game would ever surpass the sense of wonder I felt back then, but even as an adult SMO has done that.

I agree with most of what you say.
Can't say a lot about the game being repetitive as i still have to go after all the moons (been acquiring the minimum to move one, basically).

The music part is true.
I barely remember anything from Odyssey despite the 10-11 worlds i have visited.
Maybe Odyssey music is more a "matured" direction. Still, so far, don't think they created something as good as the music found in 3D World.

"I also feel that even when getting a moon in a challenging platforming level, it will not feel nearly as great because it's undermined by the hundreds of other moons that feel completely useless."
I also thought the same: the ones that are challenging to get won't feel as great - as it could feel - because of the bunch of them that are just pretty easy to get.

On the Zelda part, i agree that Zelda felt fresh and different from other Zeldas, but loving Zelda 1, i feel the game was more close to that feeling of exploration than with other Zeldas that seemed to go more with puzzle solving, for exemple.