l4d2 it has more zombies and its more funner.
yes
Yes, Download steam, make an account, search L4D2 and download the demo from there.
I have l4d, Not l4d2. But, there is no specific order. They're all different stories with the same people involved.
yes
you can't
!buy
yes
yes in verus
buy it
If your talking about L4D2 then all the content created by Valve is free.
Easy: 4000 Normal: 4000 Advanced: 6000 Expert: 8000 Versus: 6000