Always play different parts in the play or movie because it takes more then one person to the do movie or play and you need a director and editor in order to cast a play or movie. And you have to make sure you remember your part and your good at act in a play or movie plus you can't be playing around in the movie or play in order to get payed or even if it just one for fun.
Answer: The theme of Cinderella as told by the Brothers Grimm, is that if you have faith and are true to yourself, you can eventually get what you want.