We get some survival horror in Xbox Live Arcade this week with Amy. A comet strikes the Midwestern town of Silver City and the resulting virus causes chaos. Lana is an infected woman who awakens in the middle of all this and tries to find safety. Aiding her is Amy, an eight-year old autistic girl with special powers. The tandem is greater than the sum of their parts and travels together in this nightmarish world. They will work together to solve puzzles and survive the oncoming monsters. Paul Cuisset, designer of PC classic Flashback, brings us this one for 800 Microsoft Points. ($10)

Has it really been a whole decade since Halo:Combat Evolved changed the console gaming world? Its Anniversary edition is now available and it comes with six classic multiplayer maps and a seventh map for co-op firefight. They come free with a purchase of Anniversary, otherwise it’s a 1200 Microsoft Point purchase. The maps are also playable in the series prequel Halo: Reach. I need a weapon.

That Locust Horde needs some more beating down, are you up for the task? Gears of War 3 gets its Horde Command Pack this week, adding new maps, multiplayer characters and achievements. You’ll be able to unleash Bernie, Big Rig Dizzy and the Onyx Guard in multiplayer. New maps include Azura, Rustlung and a redo of Blood Drive, one of the community’s most beloved Horde maps. There are 250 more achievement points and new weapon skins. It’s 800 Microsoft Points to unleash your fury on the Horde.

It’s Halloween time, and zombies are all over Xbox Live. Zombie Apocalypse was a horror-themed dual stick shooter we reviewed back in 2009. The sequel, Zombie Apocalypse: Never Die Alone, is now available. Four new heroes find their Canadian island infested with the undead and band together. This time, the combat is squad-based. Even in single player mode, you’ll can switch between characters to use different special abilities.

Call of Duty: Black Ops unleashes the Annihilation map pack on its adoring public this week. It contains four new multiplayer maps and new zombie level Shangri-La.

Veteran players know the drill by now: New maps mean double XP weekend. From 10 a.m. PST July 1 through 5, 2011, the XP will rain down at double the regular rate. The map pack is only available for 360 for now but the doubled XP is available on PS3, PC and Wii. Celebrate Independence Day by reliving a few key moments from the Cold War. Mr. Gorbachev, tear down this wall! Annihilation is 1,200 Microsoft Points ($15).

Double Fine Productions fans, Tim Schafer’s studio is back with another arcade game. You never know what to expect from Double Fine, who most recently gave us Stacking, a puzzler starring Russian stacking dolls. Trenched is a tower defense shooter with mechs. Battle mechs and tower defense, game lovers. The studio has been doing some unique takes on tower defense, as Brutal Legend allows you to defend structures by rocking out. Double Fine, as always, punctuates the gameplay with humor. The game’s promotional materials challenge you to turn “No Man’s Land” into “Real Man’s Land.” You’re helping stave off invasion from the Monovision Menace. You can upgrade your mech by picking up the pieces of your fallen foes. There’s an RPG-style loot system in place for said upgrades. This one is 1200 Microsoft Points ($15) and early reviews are calling it a steal at that price.There has been a delay in the game’s European release.

There are no new arcade games this week but players of Street Fighter IV:Arcade Edition get four new World Warriors to take into battle. Yun, Yang, Oni and Evil Ryu join the fray in an update that also includes character balancing and enhanced replay features. It’s 1200 Microsoft Points ($15) to get your Hadouken on.

It’s a slow week with no new releases for the Xbox Live Arcade. There is a chance to keep your inner LAPD detective happy as L.A. Noire gets two cases in DLC. The Naked City finds Cole Phelps investigating the alleged suicide of a fashion model. Nothing is ever that simple in L.A. Noire. Those who preordered at GameStop get this one for free, otherwise you can buy it for 320 Microsoft Points. ($4) A Slip of the Tongue has you look into a car theft that leads to a huge auto crime ring. Seriously, in 1940s L.A. even simple crimes lead to conspiracies. If Phelps is sent to arrest a jaywalker, it’s probably an attempt to assassinate President Truman. Slip was the Walmart preorder bonus, otherwise it is 320 MP also…

There is a new Xbox 360 update that begins downloading to consoles this week.

Among the features included is more payment options available if you link your PayPal account to Xbox.com. This option has previously been available for making Microsoft Point purchases but will now be a full billing option allowing you to make payment via PayPal instead of your credit card (but, of course, you can connect your credit card to PayPal). That’s in addition to being able to purchase points or full Games on Demand. The update also adds a power conservation feature to your console. The Xbox 360 will automatically go into standby mode after being idle for more than one hour. That reduces power consumption.

Last week the Gears of War 3 beta was open for owners of Bulletstorm:Epic Edition. Now it’s available to anyone who pre-ordered the game. GOW 3 has taken numerous cues from other shooters including Battlefield:Bad Company 2. In Team Deathmatch, your squad has a shared pool of lives so you’ll need to be strategic. Running around the map trying to be a cowboy won’t earn you wins, or too many friends. Now you also have the option to “spot” enemies, marking them so your team is aware of them. This allows you to give valuable info without giving “orders,” or having to even speak to your teammate. Also, you have a Tac/Com view that shows you the location of your team (even through walls) and gun placement. During Capture the Leader, that view expands to show enemy location. The strategic possibilities are immense.