Nintendo's reticence to make downloadable content has been exasperating this past decade. Is it admirable to focus on making full games, the whole thing complete and defined when it ships on a disc? Of course, but it's also exciting to see games turn into thriving ecosystems of change. Super Smash Bros. for Wii U has already been tweaked, balanced and updated multiple times since its release last fall, but it was only this month that it expanded through big DLC. Mewtwo, the formidable Pokémon fighter last seen in Super Smash Bros. Melee, is back and we're checking out his moves with The A.V. Club's own Matt Gerardi on today's stream.