The games explain more than the films, because in the games there is no Rose - only the father, but the director apparently believed that audiences wouldn't find it 'believable' that a father would search like that.
The film was good, but I prefer watching the story unfold as DH plays the game. I missed some of the key psychological moments that explained pertinent points - like who the little girl was, and how she was conceived thanks to the damn ODEON cinema mucking it up on the big screen...