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.
Motion Sickness - One of the most common causes of dizziness accompanied by nausea and vomiting is motion sickness, which is a normal reaction to head motion. Symptoms usually start with paleness of the skin, followed by yawning, sweating and restlessness.