Varies: There is no specific dangerous heart rate during exercise. How fast your heart beats with exercise depends on a number of factors, especially your conditioning. If you are healthy, a heart reate in the 170's or even higher may be ok and tolerated.
Motion sickness caused by video games, sometimes called simulator sickness, is caused when there is a disconnect between what your eyes are seeing and what your body is feeling.
Without the motion-sensing organs of the inner ear, motion sickness does not occur, suggesting that the inner ear is important in motion sickness. The symptoms of motion sickness include nausea, vomiting, and dizziness.