Once you've completed your first game you will unlock Multiplayer mode, which you can access via the rightmost button on the menu bar.

This mode plays just like the TV show and is a local multiplayer game, so you'll need one or two other people in the same room as you to play.

Multiplayer mode has it's own local leaderboard and anything you win in Multiplayer mode is recorded on that leaderboard, not added to your Cash.