"The force of the sensors embedded in the vests "is enough to make a game fun and interesting, but it's not going to hurt people," says Mark Ombrellaro, a vascular surgeon who formed TN Games and its parent company, TouchNetworks, Inc."(Emphasis mine.)
Yeah. Because getting shot should definitely be fun. I'm sorry, but you can't have it both ways. Either the vest simulates the feeling of being shot, or it makes the game fun and interesting. The two are mutually incompatible.
Any further analysis is not forthcoming right now. My brain is still boggled.