Sunshine was great. Inception was very good too.
But Prometheus isn't at all similar to those films.
What makes great Sci-Fi? In my opinion, it's not all that different to any other genre. You need strong characters. Plausible characters. They don't have to act like you or I, but they need to be consistent. Not cowards one minute and reckless the next.
You want your dialogue to feel natural. You want your characters to say things that you could imagine your friends saying to you - things you might say yourself. You want to put your interesting characters in situations that reveal the facets of their personalities; examine their relationships. And you want it to feel natural; normal.
When I was watching Prom, I wasn't convinced by the characters. I felt they were saying and doing things they shouldn't have been. I was always *aware* of the hand of the script writer. And I had no previous bias against Lindelof, because having not followed the movie before watching it, I didn't know who was involved apart from Ridley Scott.