[Canoe]
… Unique to the 3DS version is, of course, the ability to play in stereoscopic 3D. You use the 3DS’s slide pad to rotate and tilt the board to your liking in 3D space. It’s window dressing, though; the 3D isn’t integral to game play. …
There are numerous multiplayer options too, including a mode that allows eight 3DS owners to play from a single Tetris cartridge. Network infrastructure seems solid — in my week of test time, I never had trouble finding a match in World Battle mode. …
See the full story here: http://blogs.canoe.ca/canoetech/video-games/tetris-axis-brings-3d-to-a-classic/#.TphZR3MVfJR