Hollow is a cancelled XBOX first person shooter that was in development by ZootFly in 2003. In Hollow, players would assume the role of an expelled US journalist named Tyler Kilmore, who, upon returning to the disco-totalitarian state of Centrope reunites with his fiancée and finds himself being arrested for her murder. The game would feature four distinct environments, ranging from a disco-totalitarian metropolis to a decaying underworld. Intriguingly, each mission in the game would end with a movie-style action sequence showing the player’s best moments. [Infos from Wikipedia]
It was meant to have an interesting “Psychometrics System” that based on player’s inputs and choices throughout the game, would have had build a psychological profile and offer them, among other, an ending that they want. A game of Hollow could have branch at two thirds of the story to several distinctive resolutions, and the psychometrics engine would had pick the better one for the player. The project was meant to be finished in 2005 so ZootFly had some plan to make this an “XBOX 2” launch game too.
In the end, the game was never released: it’s possible that the project was too ambitius for the team and without a publisher, ZootFly decided to stop the development.