Super Robot Wars OG-1
Set in the far future, mankind has reached the stars through the population of space colonies. However, they are not alone; the third in a series of devastating meteors reveals the existence of an alien species. This group of extraterrestrials (referred to as the 'Aerogaters' or 'Inspectors') seem to be keeping a close tab on human development, and an invasion seems to be starting. Thus the Earth Federation Army, in league with the EOT Institute, develops humanoid combat mechs known as Personal Troopers to combat this impending alien threat. Eventually a group known as the Divine Crusaders challenges the Federation's strength to protect mankind, and war breaks out among the humans.