Its all in the storyline! :)
This flash animation just goes to show you that you dont have to have flawless graphics to make a good flash. Storyline is key. This is also one of the very very fiew flash animations on NG that is serious, Not comedy.
Your checractor animation is great, I always found Posers renders to be too pixly to use in flash, and that is why I just ended up hand-drawling everything, but you have made it work.
Sound wise, If you realy want, I can give you some better sounds, the gunshot sounds bug me. Also, if I where you, id make all your sprites into flash data, so it fits with the rest of the animation.
keep up the good work