Watching them, Prometheus, Covenant, Alien and Aliens in one marathon made me realize that Alien isn't a film which aged perfectly in some regards, and I don't mean even the technical side of it, but acting, pacing and "feel" of some scenes. I also realized that some people who probably watched it for the first time and were sitting close to me questioned some of the scenes or thought they were kind of awkward.
FYI, I still think it is a masterpiece and my favourite one, and I kind of regret slightly dozing off for 10 seconds so I kind of missed the epicness of the Derelict money shot with Space Jockey, but couldn't help but point some things out.