Microsoft has announced the various updates for the Xbox Live Arcade for this week, including the Deal of the Week, the Arcade releases, and the new Games on Demand. And, once again, the new Games on Demand are geographically broken up in a manner that is as fascinating as it is confusing. Let's take a look at what's going on:

This week's deal is the original Puzzle Quest for 400. Normally sold at a cost of 800, this puzzle-RPG combo finds itself 50% off for the week. For those who have never played this addictive title, let me assure you that 400 is a ridiculously good price. It's not quite Bejeweled, and it's not quite Final Fantasy, but it's a ton of fun.

The XBL Arcade is adding two new games this week. First up is Episode 2 in Telltale's Wallace & Gromit Grand Adventure series. Entitled The Last Resort, the game follows the continued adventures of everyone's favorite British man and dog team. It can be yours for just 800.

The second addition to the Arcade is the classic Genesis game Sonic and Knuckles. The fourth Sonic the Hedgehog game, Sonic and Knuckles is available for just 400.

Episode 2: The Last Resort

Will the perfect holiday turn into the perfect crime?

When unrelenting rain ruins their holiday plans, Wallace & Gromit bring the beach to 62 West Wallaby with a makeshift resort — in their basement. Keeping customers satisfied is tricky business, especially when one of them is clocked on the head by an unknown assailant. Whodunnit? Find out... with a little help from Wallace's latest invention, the Deduct-o-matic!

The blue hedgehog and the red echidna were sworn adversaries in Sonic 3, but in the platform adventure Sonic & Knuckles™, Knuckles realizes that he's been just a pawn in the schemes of Dr. Eggman (aka Dr. Robotnik). Knuckles, the former adversary, now supports Sonic to chase the common enemy, and each must use their strengths to acquire the priceless Master Emerald and save Angel Island.

• Sonic or Knuckles: Play as Sonic and let loose on Dr. Eggman wth amazing new powers, or play as Knuckles and tackle Dr. Eggman with bare-fisted attacks, high speed glides, and wall-climbing abilities.
• New adventures: Eight new zones and two different adventures await!
• Combine games: For the first time since the SEGA Genesis, combine with Sonic 3 to play as Sonic, Knuckles, even Tails, and unlock new secrets! Combine it with Sonic 2 and play with Knuckles and all his signature moves.

And last, but certainly not least (in terms of price), comes the newly added Games on Demand. If you were thinking that the third week would be the charm for providing a solution to the geographical oddities, you were mistaken. Canada, Germany, and the United States can now download Civilization: Revolution for $29.99 (USD). Meanwhile, European Xbox owners can get their fix of Bioshock. There are also a trio of games added for the Japanese market, but as the press release was in Japanese, your guess is as good as mine as to what they are.

Here's the full details on the Games on Demand:

Content: Civilization Revolut'n
Price: Check pricing for your region
Availability: Canada, Germany, United States
Dash Text: (Online Interactions Not Rated by the ESRB) Download the manual for this game by locating the game on http://marketplace.xbox.com and selecting “See Game Manual". Legendary game designer Sid Meier brings the greatest strategy game of all time to the Xbox 360 console! Built from the ground up for the Xbox 360 console, Sid Meier's Civilization Revolution challenges you to lead your chosen nation from the dawn of man to the space age on your quest to rule the world. Go head to head with history's greatest leaders as you wage war, conduct diplomacy, discover new technologies and build the most powerful empire the world has ever known. The famously addictive gameplay, endless ways to play and Xbox LIVE multiplayer competitions, matchmaking, Leaderboards, Achievements and downloadable content will keep you coming back for more. There are no refunds for this item. For more information, see www.xbox.com/live/accounts.

Content: BioShock
Price: Check pricing for your region
Availability: Euopean Xbox LIVE regions
Size: 4.66 GB
Dash Text: (Online Interactions Not Rated by the ESRB) Download the manual for this game by locating the game on http://marketplace.xbox.com and selecting “See Game Manual". BioShock is the first-person shooter where everything is a weapon. Set in a failed underwater utopia, BioShock gives complete freedom to turn the environment, the enemies, even water and fire into powerful tools against your foes. There are no refunds for this item. For more information, see www.xbox.com/live/accounts.