Pokémon Developer Teasing New “Collaboration”

The folks over at Game Freak, the development team behind Pokémon, is teasing a new "collaboration." Over on the developer's official website, a nice big teaser image is plastered on the front page. Can you figure out what it is?
 

The text reads (via IGN): "A classic game that's played all over the world will be reborn in a surprising collaboration."
Do you have any clue what this might be? Something Pokémon-related or perhaps something else entirely? Sound off with any thoughts you might have in the comments below.