I played a pirated version of Dying Light when it launched since I didn't have any money at the time. Later on I bought this copy on Steam and had a blast playing through the campaign. The gameplay in this game is top-notch, the characters are very likable.
The story is good, it fits the promise, gives you a good concept to work for. The main hook of the game is it gameplay, parkour is very good, I think its just as good as Mirrors Edge, the feeling of freedom as you traverse through the zombie-filled-town, until night arrives...
The gameplay during the night is downright scary as f*ck, you will always be feeling nervous on your runnings. The DLC gives you new tools for traversal like the buggy and its interesting, not as good as the parkour, but not bad. The night in the camp is even scarier then on the city. I think this game is a hidden gem, it came from a complicated dev team who made Dead Island which was cool but problematic at its best, but this one is one hell of a game, don't sleep on it.