The Game is a separate virtual world within LiFe. People compete to enter into the Game during the DeathMatch and Game Trials. Inside of the game, players are assigned to Game Groups.
Players can be removed from the Game; Bloody Mary is an example of that.
The Game definitely existed before The Ending. Kleya Smith and Jake have both played in The Game before The Ending.
The Game is run basically by popularity. If you've got Watchers, you can stay in. If you're not popular, you might get kicked out. If a player gets enough fans, they might need a moderator.
The Game has a tutorial that only allows single player mode. It has various parts to it, including an Alignment part.