Zombie Machinima Animation?

First, if you dont know what machinima is i will attempt to explain to the best of my ability. machinima is a video that takes place, for the most part, entirely in a video game. the set is often a location/map in the game and the actors are models being puppeteered by players. by using a player to act as a camera (or a camera feature if the game has one, like halo3 for example) and video capture software you can film an entire video in the confines of your computer.
Short definition: its a movie made in a video game
some examples http://www.youtube.com/watch?v=Yz7dJz544ZU action trailer for a full machinima and http://www.youtube.com/watch?v=f5G2H8UC74s my favorite episode of civil protection, a comedy.

so my idea was to make a zombie based machinima with Garrys Mod10, a half life 2 mod for pc. i have little idea of story or style but i'm sure of one thing and that is ZOMBIES.
heres a couple links to different things i've downloaded for the animation.
possible setting (pictures in link): http://garrysmod.org/downloads/?a=view&id=52608
some zombies (pictures and youtube link): http://garrysmod.org/downloads/?a=view&id=52861

pretty much what i'd like to hear from you guys is your opinion on machinima zombie videos/recreations and any ideas you might have for the movie.
Thanks,
Neos