In MainPage.xaml I have 2 canvas controls (bd1 and ball) that represent 2 layers.
Code:
<Canvas  x:Name="ContentCanvas" Width="354" Height="669">
                <Canvas.Background>
                        <RadialGradientBrush>
                            <GradientStop Color="#FF9D0A0A" Offset="0" />
                            <GradientStop Color="Black"
...