Very solid game!
However, on my computer at least, the automatic weapons seem to be a little reluctant to actually shoot after reloading. Once I got the sawn off shotgun, I didn't use anything else, though.
The graphics are incredible, and it even ran smoothly on this old junk computer I'm using right now. The diaries gave it at least a little plot, but you could make the diary updates a little easier to get to next time, I guess. My final complaint is that it was actually too easy. Maybe give some of the zombies ranged weapons or spawn the occaisional boss zombie.
Not to say that I didn't love the game... this thing's getting 5'd and 10'd. Really well done!