Game is needed and Xbox as we know is created by Microsoft who powered Windows Phone OS 8.
With Xbox Live on your Nokia Lumia, you can customise your player avatar and keep up with your achievements just like you can on your Xbox console. So play a game from the selection of great Xbox Live titles and earn those achievements no matter where you are!
.... source .... : http://www.nokia.com/gb-en/apps/latest/lumia-apps/