where did you put your ParallaxScrollingBackground item, in the GameScene.qml or in the Level.qml? Because the GameScene.qml already has methods startGame() and stopGame() where you could change the running property and the Level.qml already has start() and stop() methods. In your example above however, you used startGame() and stop(). Make sure your functions are called correctly, e.g. with console.debug(“…”) messages.