Trailer description is finally up. Okay part of the story in KH3D is about "the world buried in sleep" where Sora and Riku perform their mark of mastery. The enemies in the game are Dream Eaters, which are creatures who eat your dreams. The round dog-like thing is indeed a pet companion in the game, and it can be seen floating around Sora and following him around as he performs actions in battle. It's extremely cute, and you can interact with it using the camera function (AR) and the touchpen. At the end of the trailer is apparently a scene from Xehanort's point of view, where he sees Braig talking to him asking him if his memory has returned.