I'm pretty sure David told the Engineer that he had a tiny penis, thus the angry hulk out.

Yeah, I have much praise for this film with a few reservations. The vagueness is one thing I do love about it. It's one of the few big budget blockbusters (other than Inception) that is letting the audience fill in lots of blanks intentionally. That's a big risk in a multi-million dollar flick. The Avengers can't get away with that. Does it piss so many people off that it doesn't lay everything out in an easy exposition? I guess it does. I hope if there is a sequel they remain equally as vague.

As for the awakened Engineer, I think he had the same reaction any of us would have. You know there is this big nest of roaches called Earth. You and your friends are assigned to get rid of it. The insecticide explodes and kills nearly everyone but you manage to suspend your animation so you can get your duty done. Then you wake up and the first thing you see...ROACHES!!! Holy SH#@t!  He just starts stomping those icky buggers and goes to wipe out that nest that has gotten way, way out of hand.   

The unanswered questions are what I love about this movie...and thats all. It was a big disappointment otherwise. But I'm not sure why people find it a mystery as to why the Engineer went nuts on the gang. The last thing he was doing before he went into his tube was planning on destroying the earth anyway. So when he wakes up surrounded by the very beings he was getting ready to destroy, what else is he going to do?

I do hope that a sequel is made and actually focuses on good characters and a stronger story.

 I think the engineer snapped because he Fassbender actually said: "Sorry pal, your lawyers can't get you removed from the final cut of this shitty movie. If it makes you feel any better, it's going to stink up my resume too..."

LOL mellowdoux, that made me laugh. I disagree with your sentiment but still funny

Totally agree with "monkeyfoot", i would also go berserk.

I have to respectfully disagree with the roaches comparison Monkeyfoot. I've seen the movie more than once and I noticed that when the engineer first wakes up, he's assessing the situation. He actually listens to what they have to say before he goes crazy. He even tries to understand why Shaw and Weyland are arguing.

Now I'm not saying he wanted to be "friends" or anything. I agree that his last thought was probably that of destroying earth, but I think before he makes the decision to continue that mission, he actually wants to see what's going on - then when they ask for eternal life, he tells himself "yup, continue with trying to kill em'.

besides don't you know we share 100% DNA with the engineers?? Not true for roaches. LOL. ;)

 Actually, it was just a poorly written script with pretty visuals.  No need to try to read into it.  If you were a fan of LOST you would have given up on pondering this movie's mysteries.  

 I agree with innerSanctum, in fact you can tell where the script was hacked to pieces, to accommodate the new ideas they had as the went along. I watched Alien yesterday & the spaced jockey looked very different & much more organic, also Kane said that it was fossilized, yes I know it was a different Space Jockey & a different planet, but do you know many fossilised material that is still around in the present? So much was changed, all the same people that complained that X-men first class messed with the continuity too much are the same people that love Prometheus, which destroys all the scenes that happened in Alien.  Some of the scenes which bugged me the most in Prometheus was that Ridley kept saying it wasn't an Alien prequel, then did, the android being ripped apart scene, just to say hey he's an android & look what we can do with sfx these days. The other was the Crappy proto Alien scene, which was worse, yes worse, than the Newborn in Alien Resurrection. Argh, people just kill me when they can't see a crap movie when it's staring them in the face, it's not clever except in a design sense, there's no hidden meaning, it's just another Alien cash-in.

Flinshadytoo, the reason that people can't see a crap movie when its staring them in the face is because movies, like other forms of art, is a matter of personal opinion. It is not an absolute or objective fact like the speed of light in a vacuum or when train A from Chicago should meet train B from New York.

"Prometheus/Transformers/Star Wars prequels/Fill-in-the-blank is the crappiest movie ever made. Everybody knows this! Here is the math calculations and peer-reviewed scientific observations & experiments that prove it to within .0006% error."

Sorry, it just doesn't work that way. One man's Picasso is another's child's scribbles.