Ok just got back from seeing it tonight.
My friend and I agree it's the best film we've seen in 2007-8 (and we've seen all the big films of the year!).
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You actually felt for the characters, you never know for sure where the monster came from other than it just is there. The monster looks realistic as do its siblings. The special effects were fantastic too, MUCH MUCH better than I am Legend for example and the acting was fantastic.
I instantly recognised Jessica Lucas as she's in CSI Vega (and she's so hot <3) so that was a welcome surprise.
Overall the action was thick and there was plenty of it but at no point was it overdone like in some films. What happened is what you'd imagine would happen when a monster goes rampage in the city. None of this climbing the Empire State Building guff or anything, just raw devastation and fear.
I also loved the sounds, it's one of those films where sound plays a key part in giving you a sense of realism. The subway scene is a prime example. You'd expect them to cut to the streets to show the American Army being badasses and kicking monster ass but at no point does this happen, we only hear the thundering crashes of destruction and the heavy footsteps of a beast.
Another thing I liked is that there was no "America is great we win at everything" - I liked the ending too, it was much nicer to see a bit of sanity for a change, the army exhausting standard attack options before evacuating the city as best possible and dropping the nuke.
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The film is already out on TS but I urge people to watch it at the cinema, it's the one time that paying £7.35 actually is worth it. Once again, It's one of those films you must see on the cinema!