What is the meaning of "of something" in the highlighted part?
James, his sister Sally, and Mark, their BFF (Best Friend Forever) were bored. They had played all day but now that it was dark and difficult to see, they had nothing to do. They couldn't play soccer because they couldn't see the ball. They didn't want to go inside and play a game because it was a beautiful springtime night and they liked being outside, especially after having to play inside all winter long. They just didn't know what to do and it was a little too early for them to go home. "I guess I'll just go home," Mark said in a sad voice. "Aww come on," replied James. "We still have time for another game of - of something."