As far as the writing goes, this is a phenomenal game. Most of the characters are interesting and fun to get to know and the story is pretty cool, with several different possible endings. I think the pacing desperately needed work, as it feels like it drags for a lot of the second third of the game and for some of the first. I enjoyed my first playthrough of it, but a second one feels like a chore. The writing has a lot of spelling errors that have caused me to wonder if they even had an editor who worked on it, but the story being told is 100% worth it, in my opinion.
The game market is oversaturated with zombie games, and I think this one has a lot of good gameplay and good writing that makes it stand out. It also has turned based combat which I think for the most part plays out very well, but the fog of war in that combat can cause some frustration in that you have to wait through enemies' turns without even being able to see them much of the time.
Generally speaking, I think the game spends too long with very little happening in the story, which makes sense for realism, but isn't very fun played out. If it was as engaging all the way through as it is in the last 30 days or so of in-game time, I would find it easier to recommend to people.
Another huge turn off is the sheer amount of bugs in the game, mainly in CtDs. It crashes so much that I became familiar with when to save (before bed. save before you go to bed in-game if you play this). I think this has a lot to do with running it on Windows 10, but from what I've read, the devs did regret using the engine they used because of the significant performance issues. It's also not an especially pretty game, but I personally found it really charming. If you're capable of looking past the issues, the writing has very compelling moments and I would recommend it, but I think that my fervor for a well-written zombie game fueled me personally to look past its flaws, and I don't know if everybody can feel that way.
It's also twenty bucks which, for what it is, is a lot. I recommend getting it on a Steam sale around the holidays, because it is old and there are a lot of other games you can get for twenty dollars that are more traditionally 'fun' and come with fewer technical issues.
tl;dr it's a good game with great writing and abhorrent technical problems, and a portion of the game feels like you're trudging through it. one of my personal favs, but it's certainly not for everyone.