Speedster tests your reaction time in a real life situation. Pretend you are in your car on the way to work and you have a really important presentation to give in which you are late for. You don't want to break the law, but at the same time, you want to get to work fast! You need to put the petal to the metal as soon as the light turns green.
Speedster tests how fast you can put your foot on the petal after that light turns to green. Your reaction time will be rounded to the nearest millisecond, assuring you precise results.