Dark Reign: The Future of War Windows, X360 game

As your planet and all you know are destroyed, you escape in a solitary scout vessel. Adrift in space, you encounter a probe sent by Togra himself. The probe brings you a message from Togra and the ability to transport you back in time. Centuries earlier, the planet on which Togra had crash-landed was consumed by the Imperium's Dessicator weapon. Unable to save himself, Togra sent out the probe with the hope that one of his followers would happen upon it and unlock the key that could save him. The probe can open a dimensional port that will transport you to the moment just before Togra is killed and provide you with the technology to create an army to defeat both of the warring factions, but the mechanism can work only once. If you are unable to accomplish the task, then history will continue unaltered, and Togra's fate, as well as your own, will be sealed.

To save your society, to save your lost messiah, to save yourself, you must open the dimensional door and alter the destiny of a galaxy.