As in topic, having looked briefly at code there is no "GAME SAVE" feature at present.
At least each persistent object should have a method Object_Type:: ObjectType_Memento makeMemento() and constructor Object_T:: object( Object_T_Memento ).
And also a FileSaveReader, FileSaveWriter.
The binary format might be : List of pairs : <ObjectType1, ObjectType1_Memento; ObjectType2, ObjectType2_Memento; ..... ObjectTn, Object_Tn_Memento >.
Someone should have a loook what Pattern Design has to say on that topic.