Aliens. Demons. Germans. First-person shooter fans have killed everything you can think of, including time. But it's never been so literal as in TimeShift, a new blaster with a gimmick that would make Einstein double-check his work.

That gimmick is the Quantum Suit, a $3 billion garment capable of manipulating time. As you march around an alternate, totalitarian future, meltingand perforating heavily armed guards with portable flamethrowers and spiked machine pistols, you need only tap a button to slow, stop or rewind time itself. Worried about that gang of guards? Freeze the clock and sneakily steal the weapons right out of their hands, then impishly shoot them in the face. Dodge bullets by moving several times faster than they do. Make something explode, then freeze time, jump on the debris and let it launch you skyward. Get creative.

Use your time tricks carefully and cleverly; it's a renewable but limited resource, and enemy bullets will rip you to shreds. Even on the Normal setting, the brutally difficult demo we played kicked our asses hard, but for once it's refreshing to play a first-person shooter where you don’t feel indestructible.

We spotted some things we hope will change before release, though. You can't crouch and move easily with the default control scheme, and you quickly learn that stealth and seeking cover is essential when you're out of, well, time.Why it doesn't toggle crouching on and off is a mystery that we hope gets solved. The voice acting seems a bit overdone too, but we'll suffer through that if TimeShift can deliver something new to sci-fi shooters.