This is an animation film. It may have been made before the year 2000 or around that time, but not completely sure. The only memories of this film I have is that there was a young boy who lived on what I believe is Earth or some Planet like Earth, but somehow in this world the human race are slaves to these tall giant mechanical machines. I remember this young boy was out in the woods hiding and watching some of these giant machines. I think he had a sister but not sure, but I know the plot of the film was this boy set out to discover the secrets of these giant mechanical beings because at some point I think he saw one of the machines where an alien actually got into it. I think there were a few humans who knew of what happen so long ago and these few humans hid out in caves and the forest away from the mechanical beings. This boy had heard from I think one human that hid out away from these mechanical beings a story of how the Planet of human beings were not always like that being enslaved to these mechanical beings. It seems I remember a part where these mechanical beings were looking for this boy because they found out he had seen one of the alien as it actually was. It seems I remember he discover how to defeat these mechanical beings. I hope someone can tap in on what the title of this film may be, it was a really good one. Thanks