XNA: set the mouse cursor visible / invisible

mouse visible, in Game1 constructor add
isMouseVisible = true;

mouse invisible, in Game1 constructor add
isMouseVisible = false;

XNA: Backface Culling

in XNA, by default, backface culling is on, so that we won't see the object drawn in counter clock wise order (or we won't see what is inside a ball, and we don't want to see it anyway). only primitive that is facing the camera (clock wise order) is drawn.
We can turn off culling by placing the following code in the Draw( ) method just below the
GraphicsDevices.Clear( ) method.

GraphicsDevices.RenderState.CullMode = CullMode.None;