Thanks alot alextro for your reply and capx!
But my game is something like dress-up games. I have many objects, each object has its own properties (width, height, frame number, animation, scale, color, .. etc) - not only the position of one object
And I need to detect user actions as (rotate, duplicate, delete, etc .. ) to be able to undo/redo!
So I think in saving the entire game state once an action happen by somehow!