[quote name='Corvin']I've been championing something similar over on DVDtalk. I like the way you think. My example was a zombie game where more zombies are thrown at you the higher your heart rate(or slows the action down to let you compose yourself, find health & ammo). Now imagine Left 4 Dead where it tracks everyone's heart rate and the zombies zero in on who has the highest heart rate and the remaining 3 are left to defend that one person. There are many possibilities, unfortunately people can't seem to expand their vision beyond WiiFit type usage.[/QUOTE]
Depending on exactly what the Vitality thing measures, developer's could have some fun with it. In college I volunteered for some research that used a similar system for allowing locked-in people to use computers. I was told to think passionate, high adrenaline thoughts (sex, murder, that type of stuff) to move it one way, and cool, relaxing thoughts to move it another. Wasn't the most precise tool in the world, but I was able to play a much-slowed down version of Pong with it.
If it could measure individual hearbeats, then imagine a target-shooting game where the screen vibrates in tune with your heartbeat. In order to shoot the target accurately, you'd have to slow down your heart and take the shot in between beats, just as real rifle teams need to.