Game: Hugs, High Fives and Handshakes
How do physical interactions between people change their heartrate?
No cheating (please): The game system relies on willing player participation to enforce the rules of the game world (e.g., hold your breath, close your eyes, etc.).
More the Merrier: The game is a competitive or cooperative multiplayer "party game" (i.e., based on minigames, humor, 4+ players, audience engagement, etc.), meant for one screen or more.