Good, but has a few bugs
It seems that the machine gun doesn't actually shoot if you walk around with it and click, but it does consume ammo as if you were. I also had picked up a key in the final area, but wasn't able to unlock the box that I assume had the fourth gun inside.
As for those struggling with certain enemies, it didn't take me very long to come up with a way to win. When the vampires are summoning bats, you can shoot them because they are too preoccupied to dodge. The werewolves need to be hit with your melee attack after they are stunned by a bullet in order to die. The final bosses? I'll leave that up to you. After a minute or two of fighting them, the answer will become pretty clear.