This is slightly meatier than a nano-game but you should still be able to complete it within 2-3 hours with around 5 or 6 players; it takes an amount of preparation and world-burning though, so make sure your players are up for that kind of activity.
Game Type:
Collaborative Story
Crunch:
2 - Focus/Imagination
Players:
3+
GM?:
No
Free?:
Yes
Excerpt:
This game takes place in a world that is like our own but a little bit different: in this world, telepathic powers have been appearing randomly in the global population for decades, but since there is no way of measuring or detecting them, most national governments have clamped down harshly on anyone who is even suspected of possessing them.