From the Game's Introduction:
This is a game-within-a-game, or perhaps an instance of a kind of meta-game, or a sense-of-a-game-layered-on-top-of-a-game, or maybe something less interesting than that. Maybe it's just fun. We'll see.
There is a simple party game called "Five". This involves the players simultaneously holding out a hand with a number of fingers extended. The winner each round is the one with the lowest unique number of fingers held out. The winner of the game is the first to win five rounds.
"Time Flies Like a Banana" is a game in which players are playing the roles of people playing "Five". However each player is playing the game of "Five" at a different speed.