You have to love the ambition of 343 Industries. Not only is the studio set to release one of the year's biggest games, but it's also committed to releasing five new co-op levels for the game every week once it's out. That's right. Each and every week following the Halo 4 launch, 343 will deliver a fully produced story episode, complete with five playable co-op missions. Even more wondrous still, each episode will be completely free for Xbox Live Gold subscribers.