First thing, when I'm playing a horror game, I want to be scared. I mean, hell, why else would I pick that genre?
And that, to me is the only problem in this game, it just doesn't take itself seriously enough.
In the opening scene to Left 4 Dead, it made itself look pretty serious, and when I first played through the No Mercy campaign, I was creeped out by the lighting, the zombie noises and especially that creepy music that comes on when you approach a witch. I thought it told a decent survival story, and was looking forward towards playing the next campaign.
But that's when I started to get disappointed, as right off the bat a character says "next time don't get in a chopper with a zombie" and then another one says "I think I see sunny skies ahead of us!" It was these character comments that really ruined the creepy atmosphere of the game for me. This is also the issue with COD Zombies, I mean if I was in their shoes I would be scared out of my wits, and be slowly breaking down mentally over the course of time. THAT'S how I think the characters thould be portrayed, rather then yelling "let's get em!" while fighting hundreds of zombies.
Now, that was Left 4 Dead, but Left 4 Dead 2 just takes this to a whole new level. The absurdity of the cutscene was ridiculous, and I knew from the start that it wasn't going to take itself seriously, at all. However it still tried to tell a serious story, but it failed to captivate me when the characters were howling cheesy one liners about zombies and Boomer sh!t the whole way through the entire game.
Overall, maybe the L4D series wasn't meant to be taken seriously, but why? As I said before, why play a horror game if I'm not going to be scared. What's more is that the atmosphere of the game was near perfect, the characters however were not (and don't even let me begin with the repetition of the campaigns . . .)
I still have loads of fun with it primarily co-op, but it's just these little things that keep me from being fully immersed in the game.
Save your comedy for Portal and such, Valve (as it was clearly fitting for it), and keep it out of the zombie games (which just feels out of place).
What do you guys think? Post your thoughts in the comments!