kupomogli on 23 February 2014
Between 3/1 and 3/3, register a Nintendo 3DS or 2DS AND one game, get Pokemon X or Y free.
The 3DS games that will work with this offer, according to this flyer, are Animal Crossing, Yoshi's New Island, Lego City Undercover, Super Mario 3D Land, Donkey Kong Country Returns 3D, and Mario Kart 7.
Not sure if you can register a second 3DS and a game, or if you have a game registered already and register a 3DS after if it'll work. They both probably have to be registered during that time though like FIre Emblem/SMT4 did.
