Unless I am misunderstanding what you are meaning by Serialize only objects that are marked with the [Serializable] attribute can be truly serialized. Most of the above do not seem to be. If this is not apparent in the documentation you can see this using RedGate and browsing the UnityEngine.dll. You might want to consider saving out only the Properties of the objects that you really care about into either a scheme that you cook up like name value pair strings in a text file. Serializing the entire scene graph might present problems, but I have never tried it.