Excellent Game
You've definitely made the best zombie flash-game I've ever seen. And big props on tossing in the Barett .50 and the fat lady zombie in the pink dress with the poker in her eye from the new Dawn of the Dead. Trying for those head shots was great, though it seemed like the only weapon that really changed with headshots was the .357.
My only problem was the chest armor and helmets on the undead soldiers being able to take rounds from the Barrett...though I guess it does keep the game from just being a complete joke after you get the gun.
Nice game!