It’s hard to argue that *Superman III* isn't just a letdown. I didn't dislike what was happening on screen, but I couldn't shake the feeling that it simply wasn't good. A lot of the time, it felt like the main character was pushed to the background, and even when he did appear, he seemed… downcast? It’s a strange direction for the story to take. Christopher Reeve is still decent in his role; there aren't any problems with his performance. Margot Kidder has a part, but she doesn't get much screen time, though Annette O'Toole does alright with what she’s given. Richard Pryor, Robert Vaughn, and the others are acceptable for their roles, but their characters just don’t grab your attention. I honestly didn’t feel invested in them. The beginning scene really sets the tone for what you’re about to see. There were hints in the earlier films that the people making it wanted to move toward simpler humor, and maybe it would have been okay if this had stood on its own, but as a *Superman* movie? Definitely not.

Source on TMDB