Valve Software sends word that their cooperative focused Zombie apocalypse shooter Left 4 Dead is now available for the Mac. Mac supported is accompanied by several other general bug-fixes and drops in the middle of Valve's Halloween festivities.

In addition to a big Steam Halloween Sale Valve have also added a bunch of quirky features to Team Fortress 2 that includes new achievements, new Mann Co store items, a new Map with exploding pumpkins and a "Headless Horseman" NPC that generates randomly during matches. More specifics on that one can be found over at teamfortress.com

Is today "We Love Zombies Day" or something? Adding to our growing list of games featuring the undead and the myriad media we get for them, Valve have thrown out a lifeless bone in the form of an epic trailer for their forthcoming Left 4 Dead DLC, The Sacrifice.

The cool news for this new content is that it's not version locked, so if you have Left 4 Dead you can play it, and if you have Left 4 Dead 2, you can play it too. The Sacrifice merges both L4D iterations together in a story that bridges the overall narrative; opening up the game's lore just that little bit more and creating something of a single universe. And I have to admit, this trailer is pretty sweet.

Watch it embedded below, or click here to download.

Over at the official Left 4 Dead blog; Valve have posted the first installment in a four part series of comics that provide the back story to the previously announced Sacrifice DLC which is due to arrive in October for both Left 4 Dead 1 and 2:

Welcome to the first chapter in our four-part Left 4 Dead comic, the Sacrifice! Find out what happens after the military rescued Francis, Louis, Zoey, and Bill at the end of the original Left 4 Dead in four weekly installments, each a whopping 40-plus pages of story and art. Then, download the new DLC “The Sacrifice”, where we put the story’s conclusion into your hands.

Head on over to the official Left 4 Dead blog to check out Part 1. promoted forum item

Throwing zombies into anything at the moment seems to be the correct way forward. Hell, even Treyarch threw zombies into Call of Duty: World At War, for good measure. And now, in the ever-growing expansion of the zombie game we have Left 4 Dead - quite possibly one of the finest examples of cooperative gameplay.

I don't need to say much more, so I'll let the game's packaging do it for me:
"Four survivors in an epic struggle... Fighting hordes of swarming zombies. Can you survive the ZOMBIE APOCALYPSE?"

Genius.

Hit this link for our full review, and our game page for all related media and info.

We've nabbed some new Xbox 360 screens for Left4Dead from Valve that show off some of the user interface (UI), for anyone wondering how the game will work on the home console. For the rest of you only interested in the PC version, we also managed to get an updated system requirements manifest.

To run L4D comfortably on your PC, you'll need the following:

• OS: Windows XP, Vista, Vista64
• CPU: 3.0 GHz P4, Dual Core 2.0 or AMD64X2 (or higher)
• RAM: 1 GB for XP / 2GB for Vista
• Disc drive: DVD-ROM Drive
• Hard drive: At least 7.5 GB of free space
• Video: Direct X 9 compatible video card - Video card must be 128 MB or more and should be a DirectX 9-compatible with support for pixel shader 2.0 (ATI 9600 or high. Or, Nvidia 6600 or higher)
• Sound: Direct X9.0c compatible sound card

If you want to check out anymore for this highly anticipated release, head over to our Left4Dead game page.