I really enjoyed this in the main. The start was a bit slow and jumped around a bit, there seemed to be two beginnings, one with Warren seeing the old lady zombie and leaving London, and the next where he introduces himself as someone writing about the zombies. But once we got past that blip, I found this an entertaining read. Some errors were present in wording and grammar, but these didn't spoil it for me.
The thing that did spoil this for me, was how sexist it was. While I understood that Warren was supposed to be sexist, it was more that that. Every woman was namby pamby and either stayed with the kids, cried while the men told her to toughen up, or shouted/nagged a lot but still let the men do everything. The one female character who wasn't a damp nitwit was gay and explicitly described as masculine. I really liked this character and her ending was great, but you don't have to be overly masculine to be brave or to kick a zombie's ass. I'm ok with a sexist character, but if only Warren had underestimated the women, or at least been proven wrong on some occasions when he's being annoyed with how lame they are being. To be honest, I was really quite annoyed by the time I finished it.
Overall a good read, marred for me by the sappy women characters.
It's a good story, as far as it goes. However, it's really nothing more than the first few chapters of a book "soon to come". It's not a short story, because it really has no ending to it.