Import the ScoreBoard class and create one actor object instance of it. The easiest way to 'score' for a game like that is to count the passing cycles (put a counter variable in the world class and have it increment in the act method). Use a factor of its value to determine the score (like every 100 cycles scores so many points). As an alternative, you could use real time; although, the coding is not as simplistic. As a third option, you could count the number of platforms that pass below the bottom of the window as the standard for scoring. I personally think the first option is more of a consistant scoring system and certainly the easiest to code.