You should press button STOP to the exact point in time.
You dont know how time goes if enjoy this game.
You can choice 3 modes(Easy, Normal, Hard) and each mode have 5 Level(1s,2s,3s,4s,5s).
Have fun!
It will be see you in apps in the U.S., Canada, Australia, New Zealand, Japan, France, Germany, Italy, Spain, and the U.K App Stores.