SCULLIBUNDO
Banned
Agreed. The alien in Alien was exactly that, "Alien" with a capital A. In Aliens they were giant scary space bugs, complete with a queen bee to reproduce, rather than the horrifying "people get turned into the eggs" that was in the Alien directors cut.
It's not that the aliens could no longer be scary. They WERE scary in Aliens. It's that after having seen Alien, they could no longer be that - alien. We've seen them. The unknown about their lifecycle was essentialyl revealed. We've encountered it and lived through that horror. What Cameron used to replicate that 'unknown' factor of a species that we had already experienced, was to place an enigma that bubbled under the surface throughout most of Aliens: Just where the fuck did all these eggs come from? He managed to create the unseen threat with an organism we were already familiar with.
And when Ripley accidentally stumbles into the nest with Newt and you hear THAT breathing (which is Cameron, btw), it's scary as fucking hell.