In
TimeShift, you play a scientist involved in a very secret, and privately funded, project called N.E.X.T. Your group is, among other things, attempting to develop time travel and the ability to survive such a physiologically difficult process. Your team develops two suits that protect the body from the hardship of time travel. The first one, the Alpha Suit, works, but requires a lot of manual monitoring on the part of the wearer. When this suit is stolen, and for some reason brought back to the early 1940's, you don the second suit, the Beta Suit, which thankfully has some more advanced settings, including an A.I. that tells you how to control practically every aspect of time travel.
When you follow the Alpha Suit into the past, instead of finding a war-torn Europe (this is supposed to be WWII period, after all), you find a world ruled by a scientifically advanced government - obviously someone has been messing with the time line. Paradoxes aside (and there are plenty of them), the story is enjoyable and is one of the reasons I played this game as much as I did. If the mystery of who stole the Alpha Suit hadn't intrigued me, I would have stopped a lot sooner.
Outside of the ability to slow down, reverse or stop time in order to solve puzzles and make yourself a force to be reckoned with, TimeShift is your standard FPS with a wide assortment of powerful weapons.
This game has had its hardships since production began. At one point, the game was ready to be published, but initial reactions were so low, that it was almost completely rewritten. One of the questions that were being asked about the game, even when it was first revealed, was how the players would be able to manipulate time in multiplayer games. One of the more fun multiplayer modes gives you time grenades. These grenades produce an area of slowed time so that anyone or anything that goes into it seems to stop, or at least move really slowly.