The story, features, episodes and graphics is less as compared to series 1. I finished the game very early which is quiet disappointing. One thing I like is no one to do sacrifice at any part of the game. You will come across new bosses which looks quiet similar to series 1 bosses. The same guns you will also use in this game. In 2 parts of the game, you will characters of part 1 which turns out very interesting part of the game. As per my experience, it is just a add on campaign of series one. Nothing special you will found. Overall Left 4 dead is a great game.