This game is OFF. DA. HOOOOOK
Seriously, if you're worried about difficulty, don't be. I watched videos prior to the demo and lamented the seemingly challenge-less difficulty. But actual playtime has remedied this. You CAN and WILL run out of ammo, sometimes at the worst possible moment. You CAN and WILL die on the harder difficulties. The nature of the game is that you can be doing well one moment and then shit hits the fan. It's tense as hell because you NEVER feel safe except in that blessed safe room. And regarding the zombies: trust me, there will be quite a few times that you're happy that these guys don't go into attack mode the second they hear or see you. And my god is teamwork important. You absolutely do not survive alone, period. This is one of the first FPS games that truly surprises the fuck out of you. Enemies do not simply come from THE FRONT. They come from the side, behind, below, even above. You'll be hurrying through a darkened subway tunnel when suddenly they are swarming at you from the rear, bursting from a tiny hole in the wall, or dropping from an opening in the ceiling. They climb, over ANYTHING, they break down doors, and they run fast as hell. And there's always a good chance of a boss zombie in the crowd. A boomer that vomits on you and draws every zombie in the area swarming to you, a smoker that snags you with his tongue and starts choking or dragging you away, a hunter that claws you to shreds, or the fucking tank that takes all four team mates to finally bring down. And there's the witch, known by her telltale wailing and crying. The demo has only been out a day but players have already picked up on the protocol: when you hear the crying, flashlights go off. You don't want to be the person who wakes her up.
My only main gripe, besides laggy zombie animations that sometimes warp around or behave strangely, is the terrible matchmaking that makes online play a fucking nightmare. Hope Valve gets that shit sorted out before or for release. Otherwise I am pretty happy with the game. It might be neat to see if players can create a slower paced mod that places greater emphasis on exploration and conservation, because L4D is pretty fast paced and trigger happy.
WHY SO SERIOUS HAHAHAHHAHAAHAHAHAHAHAHHAHAHAHHAHAHAHAHAHAHAHAHHAA