This NEEDS a map pack. I agree with one of the top comments that says that the game is too easy. It was lots of fun playing this, but I think it could be better if it had either more and harder levels, or a player-made levels.
Hey I found out a relatively easy way to kill the zombies, it's not hard to master, just takes a little bit of practice: Get a rocket launcher and mines, then you place a mine behind you and take care of the zombies in front of you, then proceed to finish off the ones behind you, then place another mine and repeat it, the mines make it easier for you to control the zombies, for me at least it worked, thumbs up if you did it and it worked! ^^
Really nice and I like the customization capabilities a lot! The main problem is that I get too many bp's and not so many gp, besides that, the game is great!