As mentioned, not wholly sold on David being the creator of the Alien but at least it helps to explain why he was putting the goo into drinks in Prometheus - he's just a bit mental.
GF and I both found the white skinned creatures scarier than the Alien - which is understandable as we all know the Alien so good they managed to get that right.
Loudest chuckle in the audience from the "fingering" line was from my GF. A proud moment for me
One of the few things that annoyed was the 2nd in command guy - if he was that incapable of dealing with the situation, what is he doing being 2nd in command? And his decision to not to go Orgasm 6 (a miss-hear from my GF - clearly mind elsewhere) was a bit too quick even if they didn't want to go back in the pods.
Usual other questions -what laid the eggs? If David needed biological beings to work on his creations, why wipe out the species on the planet - and why bother in the first place?
Shaw's fate reveal was a bit underplayed. If we were supposed to care for her in Prometheus then we needed more time to absorb her fate.
If this the 2nd film in a new trilogy - and only now do the Aliens exist, then maybe in the 3rd film the Engineers discover what David is up to and go find him. An Engineer befriends Daniels, explains to her why they want the humans destroyed, she helps change their minds and together they stop David. Everyone's a winner, pats on the back all round. Daniels is sent off hoping to be picked up "by the network" and Engineer guy, with fresh news that perhaps the humans deserve a 2nd chance, sets off for home. Not long into his journey, he feels unwell, a Queen bursts out his chest (I know about the egg/David thing so yeah, but being an Engineer his DNA could induce a Queen birth) and she hops off into the caves underneath the crashed ship and lays "thousands of eggs, thousands"