Earlier today at the Game Developers Conference, Super Mario 3D Land director Koichi Hayashida revealed a number of different features that were left out of the final game. According to Hayashida, not all of these ideas were taken too seriously, but there were a lot thrown out there, and plenty of them actually seemed kind of cool.
One of the concepts left out was "Pro Skater Mario." Apparently, the famous Italian plumber was going to be able to ride Koopa shells. Reminds me a lot of Super Mario 64, which allowed you to ride the shells of fallen Koopas as if they were skateboards. It was a really cool mechanic then, and it's kind of a shame it was left out of Super Mario 3D Land.
Additionally, players would be allowed to crush cockroaches in the game by closing the 3DS. As a person who hates roaches, I would have certainly welcomed this gameplay element, though we all know PETA would have something to say about it. Another neat idea was a long-limbed Mario. Basically, the plumber's body parts would grow to crazy lengths and all we'd see on the screen would be his legs.
Another feature left out from the final version of Super Mario 3D Land was the ability to replace Princess Peach's face with that of an actual person's. Like, a person you know, thanks to the 3DS camera. I don't know about that one. That's a bit odd, especially since you know there would be a creeper replacing Peach's face with the mug of the girl he likes. Yeah, kind of glad they left that one out.