website and over the Xbox Live Marketplace. The first update came as a set of specialized armor for Oblivions ridable horses; released on April 3, 2006. Although gamers generally displayed enthusiasm for the concept of micropayments for downloadable in-game content, many expressed their dissatisfaction at the price they had to pay for the relatively minor horse-armor package on the Internet and elsewhere. Hines assured the press that Bethesda was not going to respond rashly to customer criticism. New releases continued into late 2006, at lower prices with more substantial content, leading to a better reception in the gaming press. Other small DLC packs include a set of houses themed after the game's factions, a new dungeon, and new spells that were absent in the initial release. Oblivions final content pack was released on October 15, 2007. The Elder Scrolls IV: Knights of the Nine is an official expansion for Oblivion released on November 21, 2006. Downloadable on the Xbox Live marketplace for the Xbox 360 and available for retail purchase for PC users, the expansion content was included in the original version of the PlayStation 3 release. The expansion was developed, published, and released by Bethesda Softworks. The plot of Knights of the Nine centers on the rise of the sorcerer-king Umaril and the player's quest to defeat him with the aid of the lost crusader's relics. Although it made little change to the basic mechanics of Oblivion, it was judged by reviewers to be a brief but polished addition to the game's main plot. The Elder Scrolls IV: Shivering Isles was released on March 27, 2007, for Windows and Xbox 360, and December 8, 2007, for PlayStation 3. The expansion offers more than 30 hours of new adventuring, and features new quests, voice acting, monsters, spells, armor, and expanded freeform gameplay. It features a new land "that [players] can watch change according to [their] vital life-or-death decisions." Shivering Isles takes place in the realm of madness ruled over by the Daedric prince Sheogorath. The player is tasked by Sheogorath with saving the realm from an approaching cataclysm known as the Greymarch. Reception Oblivion received universal acclaim from critics, and became a commercial success. The game had shipped 1.7 million copies by April 10, 2006, sold over 3 million copies by January 2007, and over 3.5 million by November 2011. Electronic Entertainment Design and Research, a market research firm, estimates