I've not got a lot to say - but this is a remarkable 23 minutes!
The message is very strong, and the plot twist I didn't even see coming, it was of block buster budget quality.
Although, I disagree with idea it's perfect as it is. This is a small concept bubble of what it could have been. I don't think it would be utilised properly in a drawn out 12 episode anime, but as an animated movie ...