This is a rather odd request, but here is is. When you make a demo sometimes it is possible to make it so that the save files that you've developed in the demos can be transferable to the main game when it is time. Other times they are not transferable. How can you tell the difference? What does the game designer have to do to make the save transferable from Demo to actual game? This is of course assuming that the demo is just like the first portion of the game while the rest of the game will be forthcoming.