Admittedly I played the follow up game Left 4 Dead 2 before I played the first one due to a free demo being offered on the xbox live market place and winning me over instantly. After I finally got hold of some money I went and purchased this one, the game is great and I was highly addicted for a great amount of time (my xbox live statistics of 250+ hours of game play proves this) however I eventually became a little agitated and bored of it as it lacked all the new awesome exciting stuff that the second game had to offer - This one doesn't even have melee weapons which can make you want to rage quit on a number of occasions when you're finding an enormous horde of zombies with a less than satisfying gun. Which brings me to the fact that there are only a limited amount of guns available and less special infected zombies (extreme mutations of zombies that are stronger than generic zombies and have unique abilities they use to try and kill you).

You are able to play solo/ off line campaign with computer controlled team players and you are also able to play on line with friends or strangers in a public game. The team consists of four characters; Bill, zoey, francis and Louis all of whom you can take your pick to play as. The game also offers survival mode where you try to stay alive for as long as possible before being ripped to shreds, it gets both frustrating and addictive when trying to beat your best score over and over again which can be enjoyable on occasion.

I haven't found the first game as memorizing as the second one as there are limited items and the maps seem pretty dark and dull in comparison. The downloadable content for Left 4 Dead is disappointing also and I wouldn't recommend purchasing "crash course" unless you're not fussed about spending a couple of hundred Microsoft points on an extremely short level with only two chapters rather than five.

However if you're planning on purchasing Left for dead 2 as well, it's probably a good idea that you buy this too as it allows you to understand how the first characters intertwine in the follow up game as they are connected briefly in the downloadable content for the second game.
This is a thoroughly enjoyable game and many people argue that this is actually better than the second one however you can make your own mind up by buying this game for yourself.