Left 4 Dead 2 Pc Game -v2.2.2.9- ((link))

The goal is simple: get from point A to point B. There is no complex lore to memorize, no skill trees to grind, and no open world to explore. It is pure, distilled survival. The genius of the design lies in its simplicity. Within minutes of booting up the game, you understand the stakes: work together, or die alone.

If you have a legit Steam copy:

Update your game, update your mods, and survive the apocalypse. Left 4 Dead 2 PC Game -v2.2.2.9-