I couldn't help but compare "Seeking a Friend for the End of the World", which probably cost less to make than the foot massage budget of Prometheus, and which I fould to be a thousand-fold more interesting and more moving. I just think that, all too often, having too many toys to play with ruins the soup, to mix metaphors. Sometimes they manage to pull it off and all of the f/x actually enhances the experience, and spending all that time in front of green screens doesn't destroy the actors' abilities to provide convincing performances, and they don't end up seeming one dimensional, etc... But it seems to be a tough thing to do, and few really nail it.
Sometimes it just comes out like "oh, it's some people talking on this amazing looking set, followed by some people talking on this amazing looking set, followed by some people getting eaten on this amazing looking set, followed by some poeple posing with exotic weapons on this amazing looking set, etc..." To me, this was one of those. Compared to what was done in the original two movies, in terms of energy, intensity, and atmosphere, with probably a fraction of the budget, the difference is pretty stark.