Level select
Highlight the "Option" selection at the title screen, then quickly press Up(2), Down(2), Left, Right, Left, Right, L, R on controller two.
Ten lives
Highlight the "Option" selection on the title screen. Quickly press Up(2), Down(2), Left, Right, Left, Right, B, A on controller two, then Start on controller one. The "Rest" option on the options screen may now be set to ten.
One player extra continues
Press Start on controller two just before losing with no continues remaining. Game play may be continued as player two with the continue total reset to full.
Alternate music
Enter sound test mode from the option screen. Set the sound test to the "Staff" selection, press B to play the song, then press Y.
Extra points
Throw your opponents at the screen for more points and lives.