Valve is continuing to support Left4Dead2 by adding a new campaign as well as a new game mode called “Mutation Mode”. Everyone week mutation mode will change the rules of how the Left4Dead world works. The first mutation adds a Realism difficultly to versus mode. After playing this mode for 2 hours, I have to admit that it adds much to the games versus mode.

Then you have the new campaign, the passing. “The Passing” features 3 new maps, new weekly game modes (Mutations), a new “uncommon common” zombie class (the fallen survivor), melee weapon (golf club), firearm (M-60), support for infected bot play in Versus, 10 new achievements and more. All these features were added free to the PC version, but if your on xbox, your going to have to shell out 10 bucks.

Read More from valves blog below:

The Passing introduces a series of weekly game mode events dubbed “Mutations.” These are week-long runs of new gameplay modes that range from “Realism Versus” to “Chainsaw Massacre”. Each week one new Mutation is featured and the previous Mutation retired.

Every Thursday the new in-game blog will let you know of the upcoming Mutation. Once a month we will have a poll to vote on your favorite Mutation. The winning Mutation will return the following week.

Our first Mutation is Realism Versus.

For this Mutation, Survivors have all the Realism changes working against them, no glows on items or survivors, tougher zombies, instant kill witches, etc. The Infected have all those changes working for them. This makes the Jockey one of the most powerful Specials for his ability to steer a Survivor out of view. You will want to make sure you have a working microphone so your teammates can hear your screams for help. This Mutation is only available in Versus.

Another example of an upcoming Mutation is Chainsaw Massacre. You are armed with the only thing you need to survive a Zombie Apocalypse: a chainsaw with unlimited gas. Rip apart thousands of zombies on your way to safety. This Mutation will be available later and only in Campaign Mode.

To learn about the other Mutations, you will have to check the in-game blog each week. What we can tell you now is the Mutations will cover different game modes and be available across all Campaigns.

The Passing Promo Video

Valve continues to show that they not only make great games, but they also support the games months after users pay for them.

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