What can be said? Maybe: If you haven't seen "The Changeling" (1980), then how can you approach any ghost story made after? Would it be a stretch to say that if it wasn't for this film, the soundtrack of horror would have evolved entirely differently? The Japanese hair ghosts would never have been as scary? Films like "Insidious" or "Poltergeist" might never have been made? Well, maybe that is a stretch, but I think it's safe to say that all…
A case could be made arguing this film as the most important horror film of all time. No other film in Cronenberg's repertoire more succinctly communicates the meaning of the word "Cronenbergian" or the phrase "body horror".
Equal parts science fiction, horror, and psychological thriller, "The Fly" reached into the minds and bodies of a population reeling from epidemics of seemingly unpreventable disease and substance abuse and brought medical science from the subconscious to the forefront of our conscious nightmares.
No other film yet made has painted a more bleak and truthful picture of man's relationship with technology, and, consequently, himself.