Especially on the harder difficulty levels of Left 4 Dead?

I tried asking in the Steam forums, but got no answers so far, and I guess people here might have encountered this kind of behavior before. I wanted to play l4d2 demo again yester …

This achievement reads: Survive a campaign with no Survivors taking damage from Special Infected. However, invariably someone takes damage from a witch, tank, or other special inf …

The Zombie Genocidest achievement in Left4Dead requires: Kill 53,595 Infected. Is there any significance to the 53,595 number?

Most of the people I play with say that the hunting rifle is not very good compared to the automatic shotgun and the assault rifle. Are there any good situations for it?

I have the XBox 360 version of the game but I'm assuming my question would apply equally to other platforms. Are there any easter eggs or hidden levels (like the skulls in Halo) i …

I've tried to get it a few times but when playing solo (with 3 computer allies) the allies inevitably seem to startle the witch at least once. Is this something that's really only …