It is pretty simple. All you have to do is hit the 1/3 fractions and NOT the 1/2 or 1/4 hitting them will minus 1 from your score. Make sure to do all of that in the 60 second time limit. The ones on the left that are partly off the screen do not give you points.
V 1.1 Added start countdown V 1.2 No more negatives V 1.3 Fixed bugs