Trivia: Henry Cavill was considered to play Superman. He'd later go on to play the part in Man of Steel and subsequent movies.
Trivia: While the film received generally positive reviews and decent fan reception upon release, it gained a moderate amount of backlash in the years since its release due to its slower pace and lack of action in the first half. Director Bryan Singer has admitted that the film is a bit too heavy on drama and light on action, and has stated that if he could go back and re-do the film he would have cut out most of the first act to quicken the film, and would have begun the movie with the famous "plane rescue" sequence to grab ahold of the audience's attention early on.
Answer: The film doesn't take place between II and III, it just carries on from Superman II, ignoring 3 and 4 completely. Think of it as a parallel timeline.
Tailkinker ★