The Journeyman Project

The Journeyman Project is a first-person point and click adventure game that emphasizes exploration and puzzle solving.

In the year 2318, Earth is on the verge of signing a peace treaty with the alien civilization, the Symbiotry, but someone is attempting to sabotage the signing by altering the timeline. You must use the newly created Pegasus time machine to travel back in time, uncover the plot, and stop the saboteur.