Space Horde

In Space Horde you are an elite fighter. You were sent into space to stop an empire of evil aliens from conquering earth. Humanity put all its resources in one ship and all their hope in one guy... you. 

Deep inside you know it's a lost cause, but this doesn't stop you from giving your best effort so the people of earth may honour you for the rest of time. In case they survive the alien reign of course.