I received this game as a gift from someone, and I probably would've bought it myself if I knew how much fun it was going to be. I only have about two hours put in to it, but that's certanily enough time to figure out what this game is all about. Picture a mashup of the early Grand Theft Auto titles and your run of the mill zombie destruction game.
That really sums it up, but being able to upgrade your car and play around with different weapons is interesting. You will find yourself rolling around, running things over, and picking up health a good bit (or maybe I'm just bad at the game and tend to play recklessly.)
It's not something I can see myself sticking with through endgame, but it IS a fun time waster for those who are looking for something to fill the slot while they decide which next big AAA title they want to go after. I'm a big fan of indie games for this reason, they usually have a simple purpose, are easy to play, and offer enough challenges to stay interesting. We're at a point now that they can no longer espouse graphical beauty as an aid to actual gameplay or "fun factor" - graphics just don't make a game more fun. A game can be beautiful to an extreme degree and still be boring. This, however, is not boring. It's fast paced, interesting, and an oddity in the world of indie games in that it stands out by being a unique combination of largely overdone concepts.
Easily a 9/10, and definitely playable and enjoyable in small doses. You aren't, however, likely to pour 80 hours of your life in to it.