While the credits are rolling you see scenes of various Disney characters and characters from the game, including the "missing" characters of Riku and King Mickey. After the credits are finished you see Sora, Donald, and Goofy walking along a path wondering if they'll ever see Riku and King Mickey again.
A special bonus movie can be seen after the whole credits, but it can be only accessed if you seal all keyholes, get all 99 dalmatians, and complete the Hades Cup.