As you may have spotted there's a TimeShift PC demo on Eurofiles.
The one-level demo allows you to get to grips with the FPS's time manipulation features - the idea being to engage in first-person combat and puzzles by pausing, rewinding and slowing time to make the best of things.
For example, you can pause time for a spell, chuck grenades and then unpause time to watch them explode.
The Atari-published FPS is made by Saber Interactive and due out on PC, Xbox and Xbox 360. The PC version is listed as March 24th on Atari's latest schedule with the 360 to follow in May.
It's worth noting that the InstallShield used in the demo sometimes gives a "code -6001" error. Atari advises that you can sort this out by deleting the "C:\Program Files\Common Files\InstallShield\Professional\RunTime\0701" folder and, if that fails, renaming the whole "C:\Program Files\Common Files\InstallShield" folder to something else and trying again.
If you have other issues, Atari's posted more info on its forum and promises to sort out any other problems prior to release...