I wanted to like this movie. I had heard good things about it from the critics, and I liked the 1990 remake of Night of the Living Dead, so I had hopes that this might be of similar quality. Director Zach Snyder creates a mediocre film at best, entertaining, and with a good smattering of interesting scenes, but with a number of flaws as well to balance it out. He adheres to the formula that seems to typify a lot of horror films these days: take an action film, add a lot of blood, and have something jump out at you once in a while.
This film follows the general plot of the original Dawn of the Dead: zombies are destroying civilization, and a group of survivors holes up in a mall. Also as in Romero's film, the survivors have to work at being able to trust each other, although Snyder does a much more clumsy job of this, probably because he drags in so many characters that he doesn't have a lot of time to focus on the relationships between any given two, other than with broad cliches.
The cast generally does well with what they're given, though, with Sarah Polley, Ving Rhames, Jake Weber, and Mekhi Phifer playing the most notable characters. Sarah Polley plays Ana, a nurse who is woken up one morning by a zombie attacking her husband. She flees in her car, driving through a city falling into chaos, and ends up falling in with other survivors who are heading to the mall.
Much of the time, the actions and attitudes of the characters seem to come out of nowhere, motivated more by the plot and the need for an increase or decrease in tension, although there are notable exceptions, such as Mekhi Phifer's character's attitude toward his pregnant wife, which is both believable and results in a terrific scene. Polley and Rhames are also given some great scenes, saving the movie from being a complete horror-by-the-numbers.
One last thing: stay through the credits. There are some extra scenes scattered through them that should be seen to complete the movie.