Restore common variables between inherited types

I have two classes: GameObject and SampleObject : GameObject and a list of type GameObject. I've serialized instances of these classes into a XML document. My problem occurs once I deserialize (load) this document.

In XML file instances are serialized as:

<Root>
 <GameObject>
  <Type>Namespace.MyType</Type>
 </GameObject>
</Root>

Where Type represents desired type. And each instance is serialized under GameObject tag.

After parsing this document I obtain a list of GameObject. Now I need to restore correct type:

foreach (GameObject g in myList)
{
  GameObject tempObject = (GameObject)Activator.CreateInstance(Type.GetType(g.TypeString));              
}

Problem is that tempObject is blank (which is correct). I'd like to (with some shorthand) restore common (shared) variables between g and tempObject. Ex:

tempObject.Property1 = g.Property1
tempObject.Property2 = g.Property2