You are a robot that jumps from wheel to wheel, you stick to them. There are tasty apples floating in between the wheels, eat as many as you can within the given time. When you finished the apples you can go to the next level. The arrow tells you where the nearest apple is and when to jump, but mind the other robots. You can destroy them by clicking you left mouse button the moment they float over your wheel, if not, it will cost you points if they touch you.
Use your left mouse button.