You would write it in the casual form. You wouldn't write it informal because it would sound too unprofessional. And making it formal, well, some people wouldn't understand if you were to write in the formal way. They wouldn't understand the words. So just the casual way would do.
In this passage Hamlet is admiring how incredible humans are. He says they are capable of anything and represent the absolute beauty of the world, the best of all animals. However, to Hamlet, men are nothing more than dust so why do they even matter at all?
Answer:
Never go outside the Glade, unless you are a Runner.
Never hurt another Glader. You have to trust each other.
Everyone does their part. No slackers.