It’s rare for a sequel to vary so much from the original, but still feel part of the same series. Aliens did it incredibly. And they also did a great job of raising the stakes and level of conflict in a way that felt genuine rather than forced. That’s so hard to get right in a sequel. It’s almost always either a not necessary repeat of the first with some new elements, or so exaggerated in an effort to be new/bigger that it feels cheap and derivative.

Alien: Fighting an alien
Aliens: Fighting the entire hive

Then everything after that seems to have suffered from the standard problems of sequels. (Caveat: haven’t seen anything past covenant)