The idea is that 2 players fight each other (Joust) while listening to and moving at the speed of music. If you move too fast, your out. If you get pushed into moving too fast, your out. That's the idea.
It's playground meets video game.
It sounds like a lot of fun. But it makes me think, what other kinds of games/apps could combine our technologies with real-world, person-to-person, interactions?