Left 4 Dead 2’s DLC add-on is now playable to those who own the game on PC and Mac.

If you’d like a go then simply have a look at your game menu, which should now have a “Cold Stream” option. Valve have requested feedback from players through the official forum to report bugs and suchlike. Apparently the finale needs the most input, as it is likely to “change massively” once the beta has been released.

What’s now set to become an official add-on for Left 4 Dead 2 was originally simply a community campaign made by a modder named Mathew Lourdelet. Valve noticed it and decided they want it as an official add-on to be included with the next pack of DLC.

"Matthew has been hard at work on the map and the initial release looks a little more polished than you may have expected," reported the Left 4 Dead Blog.

"The reason for that is the difference between how we work on a campaign compared to modders. When we work on a campaign, we normally work in a rougher state without textures for a long period. Level design artists come in later and give the game its finished look with textures.

"Modders often texture early as they have to create the structures based on the available artwork. They don't have a team of artists coming in after them. So don't let the level of texturing fool you. The campaign is still in flux."

Apparently there won’t be a console beta, as least as far as we know, though it will be released along with the last the three Left 4 Dead 1 missions. We don’t yet know when it’ll be released but it will most certainly be after Portal 2, Valve say.