Warhammer 40k: Space Marine gives players a chance to explore their Chaotic side today.  The "Chaos Unleashed" pack has hit the downloadable market.  This will allow you to take the role of Chaos Space Marines in the game's four player co-op mode, Exterminatus.  In this mode you'll battle from arena to arena against Orks and the Forces of Man. The pack also includes three new maps, which brings the game's total MP maps up to seven.  The "Chaos Unleashed" pack is going for 800 MSP on Xbox LIVE and $9.99 on Steam and the PSN.

We were pleasantly surprised to see a new co-op mode announced for The Darkness 2.  We first brought you news of the Vendettas mode a few weeks ago.  This has been advertised as a four player co-op campaign, therefore we're expecting more than just a tacked-on survival mode.  The story will intersect with that of the main character, Jackie Estacado. The four new characters have their own unique skills, weapons, and personalities.  You  can see each of them in action in the following videos.

Rayman returns after a much needed break to bring gaming back to its roots in this 2D platformer. Beautiful hand painted art, challenging level design, and a 4 player co-op romp combine to make one amazing experience.

The Darius series of shoot-em-ups has long featured 2-player co-op play. While Darius originated in arcades, it’s far more likely that Co-Optimus readers first played Darius Twin on Super Nintendo/Wii or Darius Gaiden on Saturn/etc. The last home release, Dariusburst for PSP, sadly didn’t see release outside of Japan (but it was single-player anyway). When the arcade sequel, Dariusburst: Another Chronicle debuted in Japanese arcades last year, nobody expected it to receive a worldwide release. Now, quite surprisingly, Taito has started taking orders for an English language version of the machine.

So you've managed to get through Renegade Ops on the hardest difficulty, but you're hungry for more?  We've got you covered.  Tomorrow, on December 20th, two new DLC packs will be available for the PlayStation Network, Xbox LIVE Arcade, and PC.  These new pieces of content offer a new three-stage campaign as well as two new vehicles.

The Gunstringer got itself a little bit of DLC last week, in case you missed it.  The new content is called "REAL BIG SHOOTN'."  It's in all caps, so you're supposed to scream when you say it.  You can pick it up for a paltry 240 MSP ($3 bucks).  The new content will pit you against Mad Dog McDog and offer a variety of shooting gallery challenges that will test your air-pistolling precision.

Two years ago a platformer came along that provided such a great co-op experience it was voted as our 2009 Best Downloadable Title. Trine was definitely a welcome surprise, and it came as no surprise that a sequel was in the works. With some tweaks, the inclusion of online co-op, and a new co-op mode, do our three adventurers return to the gaming scene triumphantly, or should Trine have been a one-hit wonder?

Namco Bandai announced a little while back that Tales of Graces F would be coming to the the west, but the release date was then under wraps. Last week, however, it was announced that the game would be coming to North America on March 13, 2012. Europeans will have to wait a little longer for a Summer 2012 release (the exact date hasn't been nailed down yet, but will likely be announced soon). The european version will also be localized in German and French.

Okay, everyone, we're almost through December.  We've only got one downloadable co-op game this week, but it should be a good one.  Then it's onto January, where I'm sure there will be more co-op releases, right?  Let's take a look at the calendar here... ah crap!  Oh well.  If you're out of stuff to play you can always check out our backlog list of retail co-op games from the 2011 season.  The backlog list of downloadable games should be posted along with next week's Co-Op Release Alert, assuming the schedule remains empty.  

The Left 4 Dead fan film we told you about is out now and it's completely insane.  It's called Left 4 Dead: Impulse 76 and it starts with three characters from the first Left 4 Dead - Zoey, Francis and Louis.  They only have to make it three blocks to their target...but as you know, those three blocks are the longest of their lives.  There's no downtime here as this video is all action.

It's almost Christmas and the temperatures are getting colder.  What better way to escape the Winter blues than go to an island paradise.  There's one catch - this island paradise is filled with zombies.  Dead Island is available today on Steam for the low price of just $20, or better yet, if you can muster up a group of co-op cohorts you can snag the 4 pack for $60 - that's just $15 each.

After a bit of a hiatus, we are back with another video edition of Co-Op Classics. We'll wade through a mushroom forest infested with bugs, defend Earth's cities from incoming nukes, and take on an alien empire bent on enslaving all of mankind. Arcade Classics and Escape from the Planet of the Robot Monsters: which one of these two games never made it to your local arcade?