Tries to merge 3D and 2D gameplay and does it fairly well.
Super Mario 3D Land tries to implement 2D gameplay aspects into a 3D game and does it fairly well. Storywise we learn that Tanooki leaves blossom once every 20 years (lol) and Tanooki leaves have been spread across the land and this time not only can Mario and Luigi use them but also Bowser and his minions start using them as well. You have goombas as well as Bowser sporting tails as well.
As level design goes, it's still creative though familiar. While the level no longer rely on collecting stars, there's still a lot of puzzle solving and rooms to explore to find the Star coins and the levels do have a degree of challenge to them especially when you get the S levels once you beat the main game.
The Tanooki suit returns but Mario can't fly with it. It just allows him to hover and float slowly which helps given the game in order to be more like old 2D games removed stuff like grabbing ledges or an extra mid air move which is fine early on but those later, tougher levels I found myself needlessly dying because I couldn't grab a ledge or misjudged my jump. The 3D somewhat helps but seriously there's a reason most 3D platforming stars have either a double jump or a hover decsent. Also the first Tanooki suit doesn't turn Mario into a statue. A later version you find that's gray does allow for this though which is nice. The other new item is the boomerang bro costume which is neat for long range attacks and grabbing coins and such.
As with previous titles, if you die too many times you get the option to use a White Tanooki suit which grants invincibility as well as the magic P Wing which auto warps you to the goal. While some scoff at this. There were times when I got fed up and just used it. Plus you're more likely to die from falling which the white suit doesn't protect you from.
Once you beat the main game, a series of Special Worlds are unlocked and these are much more challenging. You get the option to play as Luigi who jumps higher but is also more slippery to control. This is where the statue Tanooki suit resides and the White suit and the P Wings don't exist here and I will say these levels were nearly frustrating at times. Many times I died because I couldn't grab a ledge or misjudged a jump or Luigi slid off the edge but if you think Mario games are too easy, give these a whirl.
Also it uses street pass where other players can give you Star Coins and powerups in Toad houses.
Overall the game is great. Not the most revolutionary game but more "new" than the "New" series. It uses the 3D fairly well and looks great and still an enjoyable title and easily one of the reasons to get a 3DS.