Make clever use of physics to collect all flags in each level. The shapes that you draw are affected by gravity, friction and inertia.
Draw the objects in such a way that they push the ball in the desired direction.
Draw a circle by holding the left mouse button. You can use pins and hinges to link two objects together. Hold S and click inside an object to draw a pin. Draw a second object on top of the pin to link the two object together. Hold D to draw a hinge.