From the press release:
March 27, 2007 (Rockville, MD) — Bethesda Softworks®, a ZeniMax Media company, and 2K today announced that The Elder Scrolls® IV: Shivering Isles™, the official expansion for the award-winning The Elder Scrolls IV: Oblivion®, is now shipping to retail stores throughout North America for Windows. Shivering Isles is also available today on Xbox 360™ video game and entertainment system from Microsoft via Xbox Live® online entertainment network.
Shivering Isles features more than 30 hours of new gameplay and allows you to explore an entirely new plane of Oblivion – the realm of Sheogorath, the Daedric Prince of Madness. Shivering Isles adds to the existing world of Oblivion so you can continue playing with your existing save game/character, or create an all new character just to explore the new content.
Within the Realm of Sheogorath, players can explore the two extreme sides of the god’s madness – the sublimely creative and the completely psychotic. Something is happening to the Shivering Isles and Sheogorath himself looks to you to be his champion and defend his realm and its inhabitants from destruction. Do you have the strength to survive his trials, tame a realm fraught with paranoia and despair, and wear the mantle of a God?
The Shivering Isles features a bizarre landscape split between the two sides – Mania and Dementia –filled with vast, twisting dungeons mirroring the roots of the trees they are buried within. You’ll encounter more than a dozen new creatures including hideous insects, Flesh Atronachs, skeletal Shambles, and amphibious Grummites. Throughout your adventure, you will discover all new items, ingredients, spells, and much more. Or, you can have the talented craftsmen of Crucible and Bliss forge new armor and weapons just for you.
Released in March 2006 for Xbox 360™ videogame and entertainment system from Microsoft and Windows, Oblivion sold more than three million units in 2006. Among the countless awards and accolades it has garnered to date are Game of the Year and RPG of the Year honors from numerous outlets, including Spike TV’s 2006 Video Game Awards, G4’s G-phoria, the Golden Joystick Awards, GameSpot.com, ShackNews.com, Voodoo Extreme, FiringSquad.com, and many more. Oblivion received the #1 ranking on PC Gamer’s (UK) list of the top 100 games of all time and is the highest rated Xbox 360 game of all time according to Gamerankings.com and Metacritic.com.
The Windows version of Shivering Isles is available at retail and is co-published by Bethesda Softworks and 2K, while the Xbox 360 version is available through Xbox Live® online entertainment network by Bethesda Softworks.