That it's 2D? Same level designs, bla bla.. I would bet you that the same people would complain if Nintendo stopped releasing them :|

Duh, people are really asking why FIFA games are rated better?

It's obviously because they have world maps!

World maps change everything!

To be honest, i found raymna origins one the best non-sonic sonic game of this gen. It's way differetn than maripo platformers.

I agree, it's very different. Too different for my tastes. I dunno, the game seemed a bit "trial and error" based to me, and required you to play levels multiple times in order to unlock all the McGuffins. It wasn't bad, but it seemed a bit less welcoming than Mario-style games.

@OP:

3D = 2D*1.5

So they were actually very generous with 2D Mario! Maths don't lie.

Maybe I can, maybe I can't. I'm not a big platformer player. You should try Super Meat Boy, Rayman Origins, Kirby's Epic Yarn, and/or Donkey Kong Country Returns if you want to see where 2D platformers have been since New Super Wii.

Story: Basically, Braid ruined Mario. Trends ebb and flow. In 2004 everyone loved super-cheesy Toby Maguire Spider-Man, and in 2006 everyone was digging good-old-fashioned Mario. In 2012 everyone wants Spider-Man to be dark and gritty like Batman, and they're tired of Mario being so idealistic. This isn't specific to Mario because he's cartoony or kid-friendly or anything -- even the old GTA games were pretty much straightforward fun. The trend now is that people want a little more cynicism in their stories. They want deconstruction of well-worn plots. Braid took the old Mario story, fleshed it out, and flipped it on its head, and everyone LOVED it. (This is all critically speaking, of course -- the average consumer is still in love with the Mushroom Kingdom of yore.) It's happening everywhere; check out Bioshock or Spec Ops: The Line. Super Meat Boy, despite its simple presentation, is pretty violent. Rayman is a bit odd, it's just very different, and the character is a bit more mischievous than Mario. It reminds me of the 90s, when Sonic and Krash were seen as more "edgy" mascots, and Mario was somewhat looked down upon by comparison.

Art style: Yes, absolutely. A minute ago I named 4 2D platformers (SMB, RO, KEY, DKCR) that blow Mario out of the water in visual appeal. You can add Braid to the list, and many others. The 3DS is a very powerful machine capable of amazing visuals, and New Super 2 didn't capitalize on that power. It kept the visuals simple, possibly to keep the size of the game down to encourage digital distribution. I've also heard criticisms that the 3D effect is poorly implemented.

Puzzles: To some extent. Take Braid, again. It mixed puzzles into its platforming (or platforming into its puzzles) to create a fresh experience. Kirby's Epic Yarn took a similar route, changing a core part of the gameplay to dramatically alter the way the game is played. Now, Mario doesn't need puzzles specifically, but it would be smart of the developers to change something in a way that makes the game play significatly differently from its predecessors.

I can't speak to bite-sized levels or user-created levels, but I can comment that many gamers have been begging for Mario to implement a create-a-level feature for a long time.

In the end, it hardly matters. New Super 2 is a great game that's going to be played by over 20 million people. In 10 years no one will remember or care what its Metascore was.

Maybe the reviewers just wants their opinion to "affect" buyers, so they are harsher with a 2D mario going for 20M sales against a more "innovative" 3D Mario. But like journalism in general, people don't care anymore about what they say so to get attention, they get even more inconsistent.

Super Mario Galaxy 2 essentially took what Super Mario Galaxy started, and expanded it to greater and more exciting levels with much more variety. New Super Mario Bros 2 did not do this by any means.

Another thing about Mario Galaxy 2 is that each level is stand out and memorable; whereas New Super Mario Brothers 2 doesn't have more than a handful of those.

Mario Galaxy 2 also feels like a world that is moving forward and that Mario is on an adventure; but New Super Mario Bros 2 just feels like levels.

I also don't agree with the assessment in the first post. If Mario Galaxy 2 is used as a standard for New Super Mario Bros 2, then the answers should be no for all of the questions in regards to New Super Mario Bros 2. 

I am not saying that 2D Mario is bad, but I am saying that Super Mario 3 and even Mario World were WAAAAY better than any of the NSMB games so far. I am also saying that NSMB2 has its place as perhaps the best game released last week; but Super Mario Galaxy 2 is arguably one of the best games of all time.