Nothing exhilarates quite like a refreshing dip in the 1950's, courtesy of Singularity's intriguing time wave.
While the Time Manipulation Device in Raven Software's Singularity allows you to manipulate objects between ages, the time wave manipulates you, forcing you to switch between present-day and the 1950's, when the titular catastrophe occurred. It's an interesting mechanic, warping the player between two different eras of a single location. At least it looks compelling now. I'm sure that by the time we get to the end of the game we'll be all, "Ho-hum, we're being time displaced again." We need to stop taking our temporal anomalies for granted.