You can abort an on-going game whenever you can access the menu bar.
To abort an on-going game:
Note: If the game is not saved or if the latest game events have not been saved, Four Winds asks you whether you wish to save the game.
Starting a new game
Opening a game
Starting the last saved game automatically on start-up
Saving a game
Sending a game via e-mail
Restarting a deal
Moving back and forth in the game
Replaying a deal
Using the Auto Play feature