Well, I'd create a layout for each of your 'screens' and then transistion between them using the "System - Go to layout" action.
So you'd start on the 'Titlescreen' layout which has all your buttons on it, and when you click on the 'New Game' button you simply tell it to go to your 'WorldMap' layout.
When you click on an area on your 'WorldMap' layout, tell it to go to the 'Game' layout with your player and enemies.
And so on.