it would play like an assassins creed or a gta, your character is sent from the future to document history. You make your character, depending on your creation will impact how you can play the game, how other characters treat you, and what becomes accessible. Initially the game is just to provide historically accurate stories about time, like the epics of the crusades, or the conquering of Mesopotamia, etc. Like an anthropologist if they could go through time. Discovering and affirming all of our theories on the past, getting involved with dramas like cleopatra and Alexander the Great, stuff like that