Select "Create Data" from the Main Menu. Pick "Register" and write "T&ESOFT" as the 10th player. You can now achieve the following effects by resetting the game and holding down the listed buttons.

Code	Effect
L+Down	"Congratulations" screen.
L+Left	Skip intro.
L+Right	"Tea Break" screen.
L+R	SNES Test.
L+Up	Credits.
R+B	"Double Eagle" screen.
R+X	"Hole in One" screen.
Y+A	Rain on courses.