I am no writer but I think this movie is about a mother has to willingly let go off her son for his own safety as there's war going on between robots and human. It wants to show you how sad it is to be a mother that can't raise and see her son growing up.
The concept may be good but I think futuristic war is not suitable. It could be a great movie if it's placed during WW, mother and son reunited after 20 years