The game comes with the new Extended Mutation System!
After releasing the popular Portal game, Valve unleashed today the Beta version of the Left 4 Dead 2 game for all Linux operating systems, via their Steam platform.Linux gamers, rejoice, as Valve released the Beta version of their Left 4 Dead 2 game for the Linux platform, including new content and the new "Extended Mutation System.”
“If you currently own Left 4 Dead 2, you should see “Left 4 Dead 2 Beta” in your library. If it doesn’t show up, restart Steam. This is a complete build of Left 4 Dead 2, so the build is as large as the current game,” the official release announcement stated.
Left 4 Dead 2 is a first-person shooter game, the sequel of Left 4 Dead, originally released back in 2008. The game is very popular among co-op fans and it’s based on the current version of Valve's Source game engine.
Being in Beta state, the game will only be playable on Valve's special beta servers.