I'm about to preface this rant with saying, unequivocally, that Left 4 Dead 2 is an excellent game. It is well worth your time and money to go out and buy it, even this soon after L4D was launched, and I've only seen a small fraction of what it has to offer.
The vast amount of new weapons, power ups and boosts make for unique and changing styles of play, not just your shottie/sniper/rifle config of the previous title. New boss infected really change things up, especially when they start working in evil, evil, tandem. And the new, non-stationary trigger events are really the bees knees - no longer do you just turtle-up, you have to go somewhere to end the event.
Again, I haven't seen all this game has yet to offer, but I'm incredibly happy with my purchase and think this is one of the better gaming experiences I could have with friends. The operative phrase there being with friends.
Seeing as all of my friends were either 1) offline, or b) haven't yet purchased the game, I decided to give it a go in the single player campaign. On normal mode. Turns out even on this setting the AI, can still be mind numbingly stupid.
This was me, Coach, the lone beacon of competency and probably the only one of my group that deserved to be saved.
The inherent problem is that the AI takes no initiative. None. 0. You couldn't get them to pick up a $1 million pile of cash sitting on the other side of the room unless you started doing it yourself. To Valve's credit, I didn't even really notice this shortcoming most of the time. I did my thing, my group backed me up. Awesome sauce.
But then, we got to a mall. And in this mall, was a door with a security alarm - a trigger event! In it, once I open the door, it's a mad dash up to the third floor to deactivate the alarm. Until you deactivate it, all of the zombies in the entire state of Louisiana, all of whom just so happen to be in the mall too, keep bum rushing you.
Something in this equation caused my team to go full retard. Valve, you never go full retard. If I could have written out the script for how this went down, it would have gone something like this.
Coach: Ok, guys, when I open this door, we need to get up to the 3rd floor and shut off the alarm. If we don't, we're going to die plain and simple. You guys got it?
All: Got it!
::opens the door::
Coach: Ok, let's get to the escalator!
Ellis: God damn it, I can't hear you, this buzzing is too loud. What about a calculator?
Rochelle: Not calculator, stupid, escalat- OH SHIT, are they having a sale at Victoria's Secret? Hang on, guys, I'll be right back.
Ellis: Actually, hold up, I might have a calculator somewhere in the gear!
Coach: What? No! Guys! Follow me, we have to get going.
Ellis: What would you even need a calculator for in a time like this?
Coach: I DON'T! What I need is some fucking support as we get our asses upstairs.
Ellis: Hang on, lemme ask this guy over here if he has a calculator.
Coach: THAT'S A ZOMBIE ::shoots zombie before Ellis can get to him::
Ellis: Well, now how am I going to ask him about a calculator?
Rochelle: [from a distance] ...Ellis! You got that calculator? I need to know how much I'm spending over here. Budgets and all that.
Coach: GAH! Ok, Nick, you'll help me right? Follow me.
Nick: You got it!
::Nick and Coach walk to the base of the escalator. Coach goes up, but Nick stays at the bottom::
Coach: What the? Nick, get your ass up here!
Nick: But the escalator's not working.
Coach: I know it ain't working, just walk up here!
Nick: Is it safe?
Coach: WHAT DO YOU MEAN IS IT SAFE? If I could get my fat black ass up here, you sure as hell can.
Nick: I dunno... I mean, it isn't running or anything.
Coach: This is the zombie apocalypse, Nick, not Black Friday. Make fucking due. It's just stairs, for chrissakes!
Nick: All the same, I think I'm going to wait for a technician. I would hate to die in something so stupid as an escalator accident.
Ellis: [in the background] My, you guys are the friendliest people I've ever met! Hugs for everyone!
Coach: I can't fucking believe this.
Rochelle: [walking up behind Nick] Hey, Coach, you have any cash on you? I left my wallet at home and I found the nicest little-
Coach: OH FUCK YOU ALL, I'LL DO IT MYSELF.
::Coach gets halfway to the next escalator when a Charger incapacitates him. Coach has only one regret just before dying: that he wasn't able to kill the rest of his team himself::
This might be funny if it didn't play out like this 3 times in a row. First time I ever ragequitted from a single player game before.