Let’s take a look at early drafts of the Alien script and it’s relation to Prometheus. The original Alien screenplay featured an unused pyramid sequence that was not filmed in the finished cut, but was ultimately streamlined with the Derelict Sequence in Alien.
Elements of that sequence appeared in Prometheus . The crew of the Prometheus find a large structure known as the “Pyramid ” much like the crew of the nostromo in alien. As Broussard (later renamed Kane) is lowered into the pyramid structure he notices the air inside is completely breathable
” …high oxygen content ,no dust. It’s completely breathable” Broussard yanks off his helmet and takes a deep breath of the air .
This is very similar in Prometheus. When Holloway and the expedition crew enter the structure and soon notice the air is breathable. Also stating the air to be cleaner than that of Earth’s.
As Broussard explores the pyramid structure he gazes at stylized stone statues depicting grotesque monsters, half anthropoid, half octopus. He approaches the centre of the room dominated by a large pedestal. On the pedestal are rows of urns. Broussard radios his crewmates stating the place is full of large bottles or jars (Although described as being leathery).
This is also reminiscent of Prometheus. Holloway and company enter a sealed room inside the large structure filled with appears to be large jars surrounding a giant stone statue . Holloway quickly flashes his flashlight at a giant mural depicting an alien lifeform and tentacled creatures .
“it’s just another tomb” Holloway says.
The dialogue is very similar in the Alien screenplay with Broussard stating
“it’s unbelievable! It’s like a sort of tomb ….”
Yet another similarity comes up when characters in the early screenplay discuss the pyramid itself. When Broussard says “Maybe the rest of the crew is in there in some kind of suspended animation waiting to be rescued” David finding the lone Engineer in stasis appears to be an obvious nod to that. It certainly seems that while making Prometheus, Ridley Scott and company clearly looked back to unused ideas and concepts from Alien to infuse in later films.
The film also (To me, at least) seems to honour the late and great Dan O’Bannon in terms of how the material was approached. In O’Bannon’s essay (Something Perfectly Disgusting ) he states “In the end I discovered that audiences supply their own answers to missing information, and it’s usually just as good as what the filmmakers had in mind, or better. Tell the audience too much and they grow bored with the film because it’s spoon feeding them. On the other hand, tell them not quite enough and they become alert and start second guessing and supplying answers, which is a more enjoyable way to watch a movie because it engages your imagination.”
In a interview published in Fangoria Magazine (Issue 239 if you’re interested) O’bannon mentioned how he would approach a sequel to the original film :
“In my opinion is that if you’re going to do a sequel you’re still under the same obligation to be as original and interesting and original as the first story ” and ” if I had done it, it would have been an entirely different movie with only a nominal link to the original and if I’m going to do that I might as well call it something different.” It’s a great interview, give it a look when you have the chance.