As a new user who bought this in a bundle, it was not immediately obvious to me how many players this game was for. It might save someone an extra few seconds if you add that it’s 3-6 players on this page.
It is not a GM-less game. It is also only partially cooperative. The players' families are encouraged to come into conflict with each other. Their characters, however, are meant to generally find grounds for working together despite the larger conflicts.