@Sitron

But then you would have to measure the time with 3 decimal places because otherwise multiple players would be in first place, especially in chapters like The Hostage

up to which chapter would the demo% go?

there is even a possibility that no one will survive as Mark sacrifices himself and North, Simon and Josh die in the revolution. Hank commits suicide by using every opportunity to remain a machine with Connor. Kara and Alice are left to die right at the beginning. And in the last scene where you can choose with Connor if you want to shoot North or spare him, you could just let the time run out and they shoot eachother. This would be a interesting categorie aswell, especially the path with connor.