While there is no doubt L4D is addicting and fun, you can't help but feel that the game is lacking content
It not only looks good, but sounds very good as well. The soundtrack is dynamic and really builds up the thrill of the moment, whether you're being pounced on by a hunter, or swarmed by hordes of zombies after being barfed on by a boomer.
The guns sound great and feel fairly satisfying, although there's nothing really new. Apart from the pipe-bomb, all the weapons feel fairly standard fair, and nothing will really surprise you there or feel revolutionary. That's not to say that the weapons are bad, they play well, and work with the zombie apocalypse experience as a whole.
Playing through the game, you will at some point wish that there were more weapons or levels. The fact that there are only standard fair weapons leaves a lot to be desired. One can't help but wonder what other deliciously satisfying ways you could be blowing up zombies, as you'll end up playing with generally one gun of your preference throughout the campaign (or switching to its superior counterpart as you find it). Furthermore, it also feels like there could be more levels, as playing through 4 campaigns over and over again (and only 2 in versus mode) makes it feel as if the developers didn't really think that any player would want more (and they do).
The AI director remedies many of the problems which would be associated with playing a level over and over again. By constantly throwing something new again, the game manages to stay fresh even though you find yourself walking through similar environments. It also helps to adequately balance the waves of enemies according to a player's gaming style to provide and adequate challenge.
All this being said, Left 4 Dead is definitely a game which you should check out. It manages to keep you engaged and entertained, and while you can't help but wish there was more, the adequately challenging and fast-paced gaming is a must-experience for any hard-core FPS fan.