See the Ending Credits
Access the ''Ente Password'' screen, enter the password A, Y, A, Right, Down, Y, Up, Right, Right, A and press Start.
Grid Racing Mode
Enter the following at the Enter Password screen and then choose a two player game.At the world select screen you'll find three new worlds where you may race.
A, Y, Right, X, Right, Up, Down, Y, Right, Down
Free for All Mode
Enter the following at the Enter Password screen. Neither player will be It.
Up, Y, A, Right, Up, Y, B, Down, Right, Down
All Flags Mode
Enter the following at the Enter Password screen. You will then have to get all the flags on each level.
Down, Y, Right, A, Right, Up, Right, B, A, Down, Start