First thing, do not expect Prometheus to be similar with any Alien Sci-Fi movie. It's not. It is a good movie. Maybe not exceptional, but have some thought about the origin of mankind and its original purposes. It feel very right and very promising in the beginning, but towards the ending it kind of lost its original purpose of the movie.
The only thing missing in Prometheus is I kinda hoping there will be some communication between human and 'The Maker'. Don't get me wrong, I always be a big fan of open-to-the-viewer-mind-ending, but I feel that Prometheus should have some background story to tell at the end. Considering the broad and rich possibility story that Prometheus could bring to us, it's a bit dissapointing and unsatisfying that the movie ends this way.
In the end, I would like to rise my hat to Michael Fassbender. Perhaps he is the best thing in this film, and sure he sets a new standard of human-droid character for any sci-fi movie in the future.