From the PDF:
Unheroes is a game for 5-9 players, that runs in 2 hours. It benefits from having a facilitator, but the facilitator can easily take part as a player.
Unheroes is about a group of superheroes from Herotopia who tried to save the world and messed up big time. Panicking, they changed reality so supers never existed, heroes or villains, and ended up living in our world with almost no memory of who they used to be. But they do remember something, and when their powers begin to return they realise something's wrong. They need to figure out what happened, and ultimately decide if they want to leave things as they are now, or go back were and try to deal with the fallout of their mistake. The game is about hard choices, consequences, and taking responsibility for our actions. Also superpowers.