It’s a big universe. If the Engineers made the Alien as a weapon, who were they fighting? Seems the scope is wide open.
Must agree that character development, along with good actors and plot is critical. Special effects adds to the movie but by itself it can not carry the load.
Hmm, unless you expect them to someday retcon* Prometheus and Alien: Covenant, I understood them to be telling us that the Engineers did not make the Alien. They made that black stuff that created life on Earth, and that they were planning to use it again to wipe out humanity as a "failed experiment".
And then the android David went mad and conducted a bunch of hybridization experiments with the black stuff, leading to the creation of the Alien we now know.
* They won't be retconning those while Ridley Scott remains a producer of Alien films.