A good story with no plotholes, well written charachters and behavior of both humans and aliens and such(Not xenos).
Dark atmosphere and story, something new and not a story we have already seen or either done really well and feels fresh.
Make the engineers to wannabes of the real space jokeys, they should be alien like and mysterious and not super humans as the engineers were. A good way to repair the damage was when they showed these engineers as the space jockeys and just tell us that they just wanna look like them and why they werent as big as the original space jockey.
Make the space jockeys/engineers smart and have their goals and not simple monsters who wanna kill us for no reason.
Maybe they arent evil at all?
Make HR Giger make more of the designs of the alien planets and such, best would be they let him decide the alien stuff and someone else to design the human designs.
Make their world fit better with what we see in alien, on Nostromo they never had holograms and all the advanced stuff they had, I doubt the crew on nostromo would have older technology on their ship than they had over 60 years ago...
Have a good writer doing the script!
Then I would have a movie to look forward to