What was the point of setting the parameter of the Prompter's constructor to (Game game)?

Craig created the constructor of the Prompter class thusly:

public Prompter (Game game) { this.game = game; }

Don't pay attention to what is inside of the body of the constructor, what I care about and can't explain is why he had to add the (Game game). Later on in the video he creates a Prompter object inside of Hangman.java and it looks like this:

Prompter prompter = new Prompter(game);

And above that line he has this:

Game game = new Game("treehouse");

The way these two lines are interacting with each other ends up being that the Prompter object is essentially telling us that its parameter is "treehouse", correct? So it would essentially look like: Prompter("treehouse");

Did I understand this correctly? And if I did, then what was the point of this? I don't understand why he would do this.