After a days worth of trial and error, I've taught myself enough to rig/animate my zombie model, and let him animate and move in game! Also, my collision detection has been fixed, and the zombies no longer walk over one another. Initial pistol model is in place with a simple particle system for the flash.
One major thing to correct for... On collision, enemies tend to bounce into the air. Probably an easy fix.
After that, it'll be GUI, SFX, and menu screens. Then first version will be complete.