Okay, first and foremost, just wanna say, I LOVE THIS GAME!! It's exactly what I have been looking for: a freeform, sandbox, open world zombie survival game. However, having said that, there are a few things you need to know about the game before buying it.
This game is in early alpha development. This means that the game IS NOT FINISHED YET. It has plenty of bugs, glitches, and unfinished systems/functions. Some things may seem a bit barebones. Basically, the game is not finished yet, indeed far from it (the finished release date is 2016 I believe!), so if you are looking for a finished, polished product, look elsewhere, or wait till 2016 and come back.
Now, on to all the MANY things I adore about this game: I think the barricading system is absolutely awesome. The ability to settle down in literally any structure, and then create a formidable defense system around it is so intriguing to me. For instance, I began my game in a small, ranch style house, and boarded up the doors and windows, and pushed some furniture against the front door. After scavenging around for a while, I found myself wanting to upgrade to a larger home, so I found a two-story building, and again, boarded up the exits. This time, I also constructed a makeshift fence around the house by driving posts into the ground and then nailing plywood boards up between them. All in all, the barricading system is awesome, and according to the developer's roadmap, they aren't even halfway finished with it yet. The combat is still pretty raw, with scoping being the only reliable way to hit things when using a ranged weapon (even at point blank I couldn't hit a zombie in the head with my pistol), but I'm sure that is something that will be fine tuned. The whole concept of the game is great, and something that is so different from any other zombie game I have played.
So, to summarize in a few words: Great game, but not finished, so don't buy unless you're okay with playing something that is a work in progress. (Still completely playable as is, just not completely fine tuned yet!)
7/10 for what it is
11/10 for what I think it will wind up being