The new campaign packs "new game mechanics, full-game production values ... the works," according to Joystiq, with Big Download clarifying that the campaign is a "direct sequel" to the original and is immediately accessible upon booting the game.
The scope of the new campaign stems from the first-person shooter's recent publisher-related delay. After the game was dropped by ex-publisher Sierra, Atari picked the game up, a move that allowed for more than nine months of additional work.
Along with the new campaign, Athena will include a new multiplayer mode and an enhanced version of Starbreeze's 2004 release The Chronicles of Riddick: Escape from Butcher Bay (PC, Xbox). Expect Dark Athena to hit PC, PS3 and Xbox 360 in spring 2009.