Dead Rising 2: Case Zero is an Xbox 360-exclusive download, available on the Xbox Live Marketplace for 400 Microsoft Points. The download serves as a prequel for Dead Rising 2, and is set shortly after Chuck and Katey escape from the Las Vegas zombie outbreak. The player must deal with a minor outbreak in the town of Still Creek, and move on before the military arrives and kills any infected (including non-zombies like Katey). The player can reach up to level five in Case Zero, with the level and any combo cards earned able to be transferred into the main game.
Case Zero was released on August 31, 2010 in North America and Europe, then in Japan at a later date because the Computer Entertainment Rating Organization was concerned about the content and the download's rating. The game is region-locked to these specific areas, and cannot be downloaded outside these regions. In the game's first week of release, 300,000 downloads were made: the fastest selling game on Xbox Live Arcade. On September 15, Capcom announced that Case Zero had received more than 500,000 downloads.
Reception for Case Zero has been generally favorable, receiving an average score of 79 on Metacritic. IGN gave the title a 6.5 out of 10 rating, criticizing the load times and the lack of things to do. GameSpot gave the title an 8 out of 10 rating, praising the fun zombie killing, in-depth weapon creation, and multiple endings that require several playthroughs. Joystiq gave the title a 4 out of 5 star rating, and recommending the game to anyone because of both the content and the price. Eurogamer gave the title a 7 out of 10 rating, criticizing many annoyances but praising the overall product.
Source: Wikipedia, "Dead Rising 2", available under the CC-BY-SA License.