Throw the snowballs so they hit the penguins and drive them into the target. A little practice on timing will help.

Use your mouse pointer to aim where Yeti will throw the snowball.
Click the mouse button to throw the snowball.

The goal is to drive the penguins into the target as close to the center as possible.
You get to keep throwing snowballs until all 10 penguins end up in the target.