All of them, the highscores in particular, the game layouts are less important
The best thing to do is make all the objects in your game have the "Behavior:No Save" (The easiest way for this to work is to add all the objects, text fields and anything else you may have to Families and give them all the No Save Behavior.) on them as the "System:Save" and "System:Load" options save and load all objects, variables and layout stances.
Let's take an example of my game:
This Screen-shot is taken from the event-sheet that will SAVE the state of the player at the end of the Layout he/she just finished:
And this Screen-shot is taken from the "Main Screen" of my game. It shows that it "System:Load"'s from the game save data it has stored from the previous layout:
If you need any help feel free to PM me directly or just reply to this thread and I'll see what I can do with your file.