Wanderers From YS III

Press Reset and wait for the American Sammy logo to fade completely onto the screen.
Then press Up, Down, Up, Down, Select and Start on Controller 2.
You must finish this code before the "Logo Screen" starts to fade off.
If it fades even a little bit, the code will not work.
When its done, and the Start/Continue screen appears, select Continue with Controller 1,
And enter any area you've been to before. Press Select on Controller 1, and select "Status." When the status screen is up,
Press Select on Controller 2 and the word "Debug" will appear next to "Status."
If you get it to work, you will still lose energy when you get hit, but every time your life meter runs out,
It will be automatically filled back up to max.

Anytime during the play of the game, press Select on Controller 1 to bring up the command menu, then press Select on Controller 2 to bring up the hidden sound test menu. Press Up or Down to change selections, and B to hear them.

Enter the Invincibility Code first, then when you fight any boss, simply press Start on Controller 2 to destroy him.