Lets start off with the warnings.
If you got sick watching "The Blair Witch Project" then you don't want to see this movie. If you're particularly susceptible to motion sickness or migraines then don't see this movie. That said, playing "Quake 2" on the slightly off TV in my parents' basement made me sick after 20 minutes or so. I didn't get ill during this movie.
The point of this movie is to show a Godzilla-type film from the perspective of the people living in the city. To do this they needed a plot device that not only explained why someone was running a video camera the whole time but why they were stupid enough to stay in the city instead of fleeing with everyone else.
The movie opens with footage making it clear that the film is property of the Pentagon. It shows a young man and woman enjoying the morning after discovering their long term mutual attraction. The time stamp jumps ahead a month to when the young man is preparing to move to Japan for a new job. The old memory card is being recorded over to document his going away party. The camera is passed off to one of those guys who is perpetually stoned by nature. Shortly we find that something happened to the couple and there are hard feelings. Then the action starts.
There's booms, shaking, and a power failure. The power comes back on. Everyone runs to the roof. Something big explodes and everyone scatters as pieces hit the roof. They run down to the street where the head of the Statue of Liberty flies in and rolls down the street. If you look closely you can just see a tentacle waving way up the street.
So our heroes get joined up in the mob heading out of town. Bad things. The young lady calls and says she's stuck. The young man must save the day. So four characters head back into town. We see TV's showing news footage, we travel through the abandoned subway, we get apprehended by the military, we climb through some ruins, etc.
We don't ever really get a clear shot of the creature. Much like the original "Alien" movie the fear factor is enhanced by not giving anyone a clear view of the creature.
The real mystery isn't what the creature is or where it came from, but where did they find a handheld video camera that works in widescreen?
Again, I enjoyed it and recommend seeing it, but I don't see a place for it in my video collection.