You are a horrible storyteller...
Ok I am not going to say anything about how you could have probably just added that to the other chapter and get rid of the whole 19 chapters thing. I am also not going to add in about how the animation seems so damn rigid...I am just going to touch the storyline.
The whole point to a story is an end, and to be honest you have left this story without and explination at all about the giants, the world in its self, what is going on with the military....there are sooo many unanswered questions.
You are horrible at telling a story, through out your whole thing you have rushed sequences over explained certain aspects while under explaining the important ones. You have made a world where there are giant robots who have arrived and run around the world....then you make a miltary lose its logic and go against the friendly giants...then you have some sort of "tinkerer" go after them, which in the end you have defeated after all that time by a simple rhyme. You did not explain anything you did not give a conclusion all you gave us was some pointy chinned girl with a bruised eye that seems to never heal and move around on her face, with some stupid life moral or whatever it was, that was a complete and horrible ending!!!!