Depressed Hangman Player

Listen up, buttercup! This joke is dark because it mixes the innocent game of "Hangman" with the serious issue of depression in kids. See, "Hangman" involves guessing letters to avoid a stick figure being hanged. So, the punchline suggests a depressed kid likes "Hangman" because it's a twisted reflection of their own feelings about life and death. Since you are the author, I think that you are that depressed kid.