A Pokémon game that looks new? Amazing. If you're wondering why the company chose to release a 3D Pokémon adventure on a handheld, though, and not the Wii U, there's a simple answer. Well, a simple answer that's different from "because we've only ever released main Pokémon games on a handheld".
In an interview with Game Informer, Pokémon Company International's J.C. Smith says "I can't speak to the specifics, but traditionally Game Freak has always loved the game to be on a portable device because of the communication, trading, and the experience of taking this adventure with you. That's why they've always prioritized a portable version of the game first. They've always liked what you can do in the real world with that."
One day, Pokémon fans, there'll be a proper game on a home console. One day.
Maybe.
Pokémon Company International Plays X And Y Close To The Chest [Game Informer]