Prometheus and Alien: Covenant are different in many ways, but having broken an unwritten franchise rule may have killed Prometheus's chances for widespread critical success. The Alien franchise is well over 40 years old at this point and yet it continues to get attention as one of the most popular horror/sci-fi series of all time. The more recent films however haven't made quite the same impact as the original trilogy.
Initially, Prometheus was set to be an Alien prequel film that would uncover where the terrifying Xenomorphs came from. It is easy to make the connection considering the alien humanoid which appears in the trailer and marketing is the same species as the Pilot from the start of the original 1979 film. So why did Prometheus avoid using the prefix that marked all of the Alien films before it?
Prometheus left the Alien pre-title behind it in favor of focusing on a new breed of alien and an entirely new planet. Instead of parasitic face-huggers, the giant and ancient Engineers in Prometheus are shown to be extremely advanced with the ability to manipulate genetics and create new species. With such a different story to tell, director Ridley Scott has made it clear that this is a distinctly different film and not in fact a prequel at all.
Why Covenant Tried To Be A "True" Alien Movie Again After Prometheus
While this was Scott's intention for Prometheus, it's clear that early audiences thought it was meant to be a direct tie-in with the popular Alien films. Instead of being viewed as a unique sci-fi story, it was dismissed as lacking many of the elements that made the franchise great. If it was truly meant to be a separate tale, why did it happen on a world close by, and why did a much more familiar Xenomorph-like creature emerge from the Engineer following the credits of the film?
The truth is, it appears that Scott was a little confused in his approach to creating a non-prequel movie based in the same universe, slightly earlier, and featuring several types of characters who would be connected to each other. However, he fixed that mistake with Alien: Covenant. Prometheus and its sequel share more similarities and explore the two species in greater depth in an effort to tie it all together. By repairing the problematic timeline and movies that weren't meant to be connected, Scott attempted to bring the franchise back to its roots, name and all.