Avoiding making people sick is one of the key struggles in producing VR games. Developers large and small have said games need to be made in new ways to protect players from motion sickness.
Virtual Reality’s Next Hurdle: Overcoming ‘Sim Sickness’
One problem is the resulting “postural sway,” or postural instability and hand-eye coordination challenges.
Additional reading: http://www.augmentedrealitytrends.com/virtual-reality/sim-sickness.html
my note: similar issues with Google Glass. Here is some more info on the issue:
Rethinking Motion Sickness
Pls have other IMS blog entries on Google Glass