Mario leaps into the third dimension.
Super Mario 3D Land may be the first game to truly replicate the feel of the original side-scrolling Mario games in three dimensions. Super Mario 64 was more of an adventure game, Super Mario Sunshine refined these adventure game elements but at the same time brought the series closer to the original platformers, and the Mario Galaxy series almost brought the series all the way back to its roots, only with the strange gravity-centered gameplay. In Super Mario 3D Land however, you're tasked with the mission of running from the beginning of every level to the end. Sure, in between you have the opportunity to pick up some giant coins that are intentionally left in difficult-to-reach places, but at the end of the day your goal is to run from the beginning of a stage to the flag at the end. There's no searching for a character who wants you to beat someone up for them, no hub world for you to hang out in, and never really any question about what you have to do next.
Mario's abilities have been scaled back more than a bit from other games, almost to the point where he resembles himself from the earliest platformers in the Mario series. There is no punching or kicking, and he can't pick anything up either. There aren't even any Yoshis in this game, if that matters to you. Mario fights by jumping on his enemies heads, throwing fireballs or boomerangs if he has the ability to, and just plain staying out of his foes' way if need be. The way that things have been scale back feels natural after a while, helping in this apparent attempt to merge the newer three-dimensional Mario games with the platformers of the series' roots.
3D Land lays on the references to Super Mario Bros. 3 pretty heavily. You'll see the return of the Tanooki Suit for the first time since the days of the NES, the mushroom houses that dispense items return, and you'll see the strange colored blocks that closely resemble the ones that dotted the landscape of Mario 3's stages. Many of the enemies have been given raccoon tails, which allow them to fly and swing them at Mario in some sort of effort to attack him. Even the mini-boss from the fortress stages returns to fight Mario, although this time it happens at the end of airship stages (another holdover from Mario 3).
Streamlined level design and a focus on nostalgia could've hurt 3D Land, but instead this game benefits greatly from its little design quirks. While its true that this game can feel easy at first, it never seems like the stages are lazy or bland. When you make it to the special bonus areas that are available after you beat the original eight worlds, things can begin to get really hairy. Likewise, leaning too heavily on nostalgia could've made this game seem like more of a cash-in than a new entry in the Mario series. Fortunately though, the level design is so tight and the little nostalgic things fit in so well that they don't make the game feel like an advertisement for older entries in the series.
The game doesn't lean too heavily on the game's 3D effects, except for those occasional moments when something travels directly at the camera just to show off that this game is in fact visible in three full dimensions. You will find the odd puzzle or two that requires the use of the 3DS' 3D capabilities, these challenges are rare but they aren't very hard to find. Personally, I'm used to the 3D effects this system produces, so I had them turned all the way up the entire time I played this game so that none of them really seemed out of place and I never really noticed a difference between the levels with the effects on and the effects off.
The art design heavily resembles that of the Mario Galaxy games. Everything is bright and shiny and has just a tiny hint of light bloom behind it to make it sparkle. Its the same rendered art style that Nintendo has been playing with since the Nintendo 64 days, only now they've learned to add so many tiny details that it doesn't appear cold and sterile any longer. The audio is another high point, most of the first-party games on the 3DS have had excellent music and this is certainly no exception.
A new Mario platform game on a Nintendo system is almost always a given (remember that the Virtual Boy never had one). Mario 3D Land manages to stand out from the rest of the series though because the developers have honed the level design to the point where it resembles the layouts of the oldest Mario games which would get stuck into your subconscious long after you had moved on to some other game. If you own a 3DS then chances are already pretty good that you have this game, but if you don't then you probably should.