I'm looking for an animated feature length movie, possibly 2nd or 3rd movie in a series where people of the earth leave the earth on a big spaceship due to possibly pollution and the protagonist somehow gets separated from the main ship in his smaller space jet.
he then crashes on another planet where his spaceship's technology is used to make other similar space ships and they combine to form a mecha.
at the end of the movie similar things happen to the new planet and her people has to leave. the protagonist then realises that the second planet is in fact the earth itself. i'm not sure of this part, he may just think the 2 planets are similar and in fact he's travel may not be in time.