Timeshift was an fps which featured interesting time mechanics.
The plot of Timeshift reminds me of The Journeyman Project game series, or the movie Time Cop. Some company invents two time machine prototypes. The founder steals one of them and changes the past to make himself the ruler of the world. You have the other prototype and need to set things right. The game was published by Sierra, so presumably it’s a third person adventure game.
No…wait…it’s a first person shooter. But there are cool time mechanics, where you can slow down, speed up, or partially rewind time to suit your purposes. The game got pretty good reviews (but not great) and came in a standard small box with a gatefold cover.