Katamari Damacy creator Keita Takahashi has lots of ideas for creative play. He's tried his hand at playground design, and helped make the Flash-based MMO Glitch. Most recently, several of his game concept designs have been put into action at the Babycastles Summit, an arty games festival in New York City's Museum of Art and Design.
One of these concepts include a projection of a playable Ms. Pac-Man that fills the entire room. Part of the game is being able to move your neck around to see where your Ms. Pac-Man is, and then dealing with control flips when travelling from wall to ceiling. Kotaku has some footage of the game: