After a strange race of alien bugs conquered Earth in what was known as the Great Catastrophe, what was left of Humanity had to escape and find shelter in remote parts of the galaxy. The scattered rests of human civilization are now betting everything on their last hope: sending you, the best of their elite forces back in time to infiltrate Earth right before its collapse with the most advanced mecha technology, in a desperate attempt to save at least one timeline from destruction. If you fail, another timeline will be left behind. You will keep fighting, over and over, until you can find one where we can end this war and save Earth for humanity…