Very nice take on the zombie genre...making a creature that's actually kind of scary. And I have to disagree, this isn't like Romero's movies, besides the whole cannibal disease spread by bites....
But now for some crit! The very first scene was the best, although your walk cycles were still a lil funky. The zombie falling from the building was very cool. And the scene where everybody is running helps establish fear of the creatures, because they kill almost at will. What was bad was the rubble and the road...I didn't really know what I was looking at for scenery. Did the road get destroyed? It was all so busy and cluttered, without any real form. But this scene is scattered with well animated bits, like the guy jumping over the car, the zombie shooting spikes at him and he dodges them, barely, among others. And in the final part, (do I need to mention the soldiers voice? wtf was wrong with it anyways? XD) when the soldier throws the card, that just seemed cliched. And it would have been nice to see the soldier kill more than one, just for kicks.
One final piece of advice...either get someone to edit your text, or type it in a word processing program and then copy/paste it into flash, because your grammar is pretty bad, and detracts from the story. Not to be mean...lol.
Oh, and by the way, I don't usually crit people like I have your past couple animations, but I can tell that you have been and are going to improve (and in a big way), so I figure you could use the pointers...although I'm not sure you didn't already notice most of them yourself...XD, sorry if I'm annoying.