In all the roles are well played and add to the believability of the film. The real star of this film is the director James Cameron. He is not an overly prolific director, very careful as to the projects he chooses. In this way he can spend far more time on the details of a film than the directors that seem to crank out a picture every year or two. Detail is the name of the game with a Cameron film.
Every scene is shot to perfection.
The staging is set like a Broadway play, every prop in place, every actor precisely on their mark. The camera and microphones becomes an extension of the audience's eyes and ears. Typical of a Cameron film there are many, many special effects. Rather than use them to carry the story Cameron takes great care with the computer generated effects he loves so well to make them integral to the plot as well as the action. The people carry the story while the effects just makes it more believable and interesting.