Mirror’s Edge is a first person platformer video game developed by DICE (EA Digital Illusions CE) and published by Electronic Arts. The game was released on PlayStation 3 and Xbox 360 in November 2008. [Info from Wikipedia] Before working on the real game, DICE tested the first person movement with a target render / prototype video, using canned animation as a target of how it would feel in the final game.
At this stage Faith was a male and it still had a gun. DICE held a presentation of the game at GDC09 and shared a proof of concept video with the fans as a “documentary” of the development of the project. Also, in the beta version we can notice some minor differences in the level layout. You can find some more info on X-Cult!
As mentioned in the bonus section of the game, a prison level was cut from Mirrors Edge for unknown reasons. Some early concept arts of the characters can also be unlocked in the bonus section.