Awesome!
You know, the first thing this reminded me of was a web-based game known as Urban Dead: it contained a building to barricade, several guns to choose from, countless hordes of zombies, and even fellow survivors. It was almost as if I were playing the same game, except with real graphics, lol.
Graphics: 9, great, but nothing too flashy.
Style: 8, good, although the zombie survival thing has been done to death by now.
Sound: 7, good, not much music, although the sound effects were satisfying.
Violence: 10, A hell lot of violence.
Interactivity: 9, You got me to play the entire game.
Humor: 5, I laughed when the army soldiers fell flat on their back from getting shot in the leg. Or when I somehow managed to kill one with a headshot!
Overall: 9 A well deserved nine. This was pretty good for a first flash submission.
*thumbs up*