TimeShift is a 2007 first-person shooter game developed by Saber Interactive and published by Vivendi Games. The game was released for Windows and Xbox 360 in October/November 2007, and for PlayStation 3 in November/December. It received mixed reviews from critics.

Scientists from the near future have begun work on creating a viable time machine. The project results in the creation of two devices: the Alpha Suit, a prototype jumpsuit, and the Beta Suit, a more advanced, military-grade model with features the Alpha Suit lacks such as combat-related time manipulation abilities and an integrated artificial intelligence named Strategic Systems for Adaptable Metacognition (or S.S.A.M.) designed to assist in combat and to prevent the creation of temporal paradoxes.

The director of the project, Dr. Aiden Krone, rigs the laboratory to explode, takes the Alpha Suit and travels into the past. Once there, he uses his knowledge to alter the timeline, placing himself as the ruler of the Krone Magistrate that controls a dystopian world.

The protagonist, an unnamed fellow scientist (originally intended to be called Michael Swift), takes the Beta Suit and follows Dr. Krone back to the year 1939 in an alternate timestream to a place called Alpha District. The protagonist travels through the battle-torn city and witnesses the rebel forces being violently suppressed by Krone's army. Eventually the protagonist comes face to face with the Sentinel, a giant walking fortress. Faced with certain death, S.S.A.M. activates "auto-return", transporting the protagonist back in time to safety. During the transport, however, parts of the Beta suit are damaged, rendering the protagonist unable to revert to the original timeline. The protagonist is forced to assist the Occupant Rebellion against Dr. Krone in hopes of salvaging parts from the Alpha suit.

The protagonist fights alongside the Occupants in Alpha District, saving many of their members and supporting their raids. He meets Commander Cooke, leader of the Occupants, and is tasked with carrying out several operations, including rescuing POWs and destroying Krone's munitions plant. Faced with military losses, Krone retreats into the Alpha District, while the Occupants raid a Zeppelin factory and hijack a Zeppelin to pursue the rogue scientist.

The protagonist returns to Alpha District in an altered version of when he first arrived, only this time the rebels are dominating the battle. Krone confronts the protagonist in a giant war machine named the Sentinel, which the protagonist ultimately manages to destroy. As an incapacitated Krone emerges from the wreckage, the protagonist executes him and retrieves the part required to repair the Beta suit. He is thanked by Commander Cooke and returns to the original timeline to save his girlfriend, Dr. Marissa Foster, who had originally been killed by the explosion Krone had caused. He shuts down the bomb and walks up to Foster, who begins to wake up. As he begins to remove his mask, S.S.A.M. warns him of an imminent paradox and transports him away to an unknown destination.

Short flashback sequences are shown at various parts throughout the game, which reveal that the protagonist was in contact with an unknown third party, was keeping watch on Dr. Krone in case he goes rogue, and has seduced Dr. Foster specifically to get access to the Beta Suit.

The key feature of TimeShift is the player's ability to control time: slowing, stopping or even rewinding time more or less at will. This allows a player to stop time to dodge an incoming projectile or steal an enemy's weapon. Specific time-related puzzles also require these abilities. The player's abilities also affect the color of their environment in such that slowing time produces a blueshift, rewinding it produces a yellow haze, and stopping time creates a white filter "haze". The player must use them wisely to make its way through the game. In some parts of the game the time powers are lengthened.