Make back button go back once

[Magalii]

Right now, pressing the back button of the phone brings the user back to the main menu. This is not optimal behavior since we usually want to go back to the previous screen and not go back to the home screen of the back. For example, when in Game 1 or Game 2, the back button should bring the user back to the World 1 menu allowing the user to choose between Game 1 and Game 2.