What is the point in the Boo Radley game in Chapter 4?

In Chapter 4, Jem pushes Scout in the tire directly into the Radley yard where she crashes into the porch. Scout is stunned when she exits the tire and Jem is forced to run into the yard to retrieve the tire. Although Jem was afraid when he entered the yard to grab the tire, he tries to act like it was not a big deal. Shortly after the incident, the children are drinking lemonade when Jem announces that he has a new game that they can play. Jem then suggests that the children play a game where they reenact Boo Radley's life story. Scout mentions that Jem's head was transparent and he obviously created the game as a way to prove that he was not scared of Boo. She also says that Jem wanted to contrast "his own fearless heroism" with her cowardice. Other than Jem's motivation to prove that he is not afraid of Boo Radley, the game also serves as a new form of entertainment. The children were sick of playing other games and found the Boo Radley game entertaining. Dill and Jem are especially entertained, while Scout experiences feelings of trepidation while playing.