Interesting idea!
Finding characters who subtly react to your movement as you walk around created a nice sense of tension. I also really liked the art style.
However, because there were only a few types of civilians, it eventually became easy to tell regular characters from spies at a glance, which removed some of the intended mind-game aspect — I found myself identifying them almost instantly without much hesitation.
Still, I think this is something that could easily be improved as the idea expands. Really fun experience overall!
(This comment was written using a translation tool.)