This film was enjoyable to watch until you learn that the hero is actually the villain. But that is quickly forgotten as he kills the problem that he and his people created in the first place, hailing him a hero amongst the people he saves.
He basically confesses to participating in genocides and then kills the last survivor and its child. He carries out no form of retribution whatsoever.
It gets worse when he kisses the 'princess' and you know he was married. Shortly after it is shown that his wife died in the spaceship he arrived in, it really came across as like an after thought.
This film demonstrates how you can do terrible things but hide it, like colonisers have done all around the world. Eg Winston Churchill who is hailed a hero because he won the war, even though he killed millions of innocents without a second thought. But that is covered up and forgotten. In fact Winston didn't feel guilty about it at all and was openly racist.