Not a lot of plot in the movie, it was a conceptualization of an alien invasion from a soldiers point of view. A lot of confusing explosions, quick action sequences, and half seen horrors, exactly as you'd expect a full blown combat situation to look like.
The dialog and acting are heavy handed at times, but for the most part it worked. You don't go into this kind of movie expecting Shakespearean subtlety in wording and Sherlock Holmes puzzle solving, you want to see explosions and guns and that what this movie delivers.
Not much more I can say without going into details other than I would highly recommended seeing this in a theater, the action is meant to be seen larger than life. Watch it if you've ever enjoyed a first person shooter video game, if you enjoy seeing hero's and villains, and watch it if you like ass-kicking.
On the other side of the coin, check out Roger Eberts review here, but only if you need to be reminded that smart people can actually go out of their way to miss a point. Seriously, the only way I see he arrived at his conclusion is if he actually knew what the movie was supposed to be delivering and he specifically designed his review to see it from the wrong point of view.
