Zombies + good flash skills = Awesome
Firstly, there are zombies. That's enough to get a 5 overall right there.
Secondly, animation is great. 'Nother 2 points.
And 3 points for a story that absolutely rules. Nothing better than the tale of the survivors after a zombie attack, and you managed to capture the chaos of a zombie outbreak with some excellent stills. Fantastic! Plus, the zombie attack is genuinely surprising (and this goes for the first two Zomborg movies as well, which I most eagerly watched after seeing this one).
Excellent work man, I can't wait for part 4!