The main new feature is squads! You can now press the Enter key to call for help. When you do, the surrounding humans will circle you wherever you go. I find that about 3 or 4 is a suitable size because they can get in the way of you getting a good score but there is no limit (so long as you can get yourself in the middle of them all).
When you shoot a zombie, you score a number of points equal to the number of health points you hit off a zombie. One bullet (currently) scores 5 health points of damage on the zombie. Each zombie has 100 health points, so killing a zombie on your own gets you 100 points but getting a multiplier on your own is very difficult.
Also, when you are turned into a zombie, you must collect an antidote to turn back into a human. So there still isn't a way to lose... I'm still working on that.
Here's a game-play video to wrap things up. If you can, please "like and subscribe" me on YouTube on my video here. If not, here's the video anyway:
Thanks everyone for reading and watching, see you next time.