Excellent horde shooter that keeps things hard and unforgiving. Completely outclassed by its successor due to a severe lack of content variety but not in terms of atmosphere, which is still unique in that aspect. The game also has memory load issues since its launch and occasionally crashes (mind that i have a high end pc), but Valve will probably never fix it. Coordination is essential to not get blocked by special infects but unfortunately the L4D community has severely abandoned this game. Players are scarce and those who are still present are mostly trolls, i advise to avoid it altogether and play with friends if you can. Since its campaigns are few, you'll soon switch to L4D2 and never touch this again probably.