It's the western name of Monster Hunter X, released late last year in Japan.
As you'd expect from the series, you're still gonna be hunting monsters with ridiculously huge weapons in wild locations.
To celebrate te game's release, Nintendo will include some content from the Fire Emblem series with Marth's armor being in the game:
Look for Monster Hunter Generations this summer. You can find our preview of the Japanese version here. Capcom will show the game on Twitch today at 7PM GMT/8PM CET.