Awesome!
First of all I have to say that this is awesome, and it deserves it's 3rd place. But I know how useless reviews saying "awesome!" are, so I'll do my best to say everything that was somewhat bad (or the things that wasn't as good as the rest).
So let's start with the movements of the characters.
The heads, and guns, were animated were good. The bodies and foots wasn't that good though. For example when they were talking, or aiming at something, the body was just still and only the head and hands were moving. If you could make the body follow in the direction that the head and hands are heading, it would look much better! I know you did one some places, but doing it all the time is better :)
Also, some of the effects could be better. I'm mainly thinking of that white-lines thing. It looks... plain, I think. Maybe that was what you were aiming for, but making it glow or something would make it look all badass ;)
And please, keep the flashback-thing, it's really something new and it totally stands out from the rest of all the madness!
So, good job, and good luck on your future projects :D