Awesome demo! Probably my favorite game in years even though it's not even fully released.
For ideas to expand on the game, I'd find it interesting for characters like Noire from a previous timeline or other characters from different timelines to have unique dialogue based on if you won against them, lost against them, ran away or begged for forgiveness on the last encounter. Also I feel like playing as Noire compared to Root is very bland, since Roothas way more unique/interesting gameplay.
Again awesome game/concept, very hyped to see where this is going