So all that needs to be done after that is to move to each keyframe where the snowball strikes the ground, and scale it down to show how it squashes on impact. On each impact I've scaled it just a little less, because it's falling from a lesser height with less force, and so it won't squish as much.
And that's it. We'll continue building on this animation (and building our snowballs to make a snowman) with a few more effects in the next lesson, but for now this is all we need to demonstrate these techniques. To see the Flash version of this (with the gradients and colors intact), click here.