Gah, major bug: in the East Area, when the manhole opens and werewolves start swarming out, the game freezes. At first I thought it was because I got into melee range of it and it got confused, but I kept my distance the second and third times and it still happened.
It's still a great game just like the original, but it doesn't feel like you added much. Perhaps I will run into more new stuff further in, but I'm halfway through and...well.
Oh, and one very minor picking point--the Ambush Zombies are a neat addition, but simply reversing the "dying" animation for them getting up was a bit lazy. It looks weird when the zombies who hold weapons get up--the weapon just magically drifts into their hand as they rise.
Anyway, aside from these very minor criticisms, this is just as fun as the original. I do hope your next game has more new toys to boast, but I expect to waste several more hours on this yet!