Valve famously made Left 4 Dead 2 free to own forever on December 25, 2013 , which caused Steam servers to crash due to high demand.
The game follows four new survivors——who are immune to the "Green Flu," a disease that turns humans into hyper-aggressive zombies. Set in the Deep South, the story spans five main campaigns that form a cohesive arc: Left 4 Dead 2 Free Download (v2.2.2.6)
Virgil’s boat runs low on fuel, forcing the group to trek through a hurricane to a gas station and back. Valve famously made Left 4 Dead 2 free