Hissatsu Doujou Yaburi (NES)
CheatingDome.com
Invulnerability
Press and hold Up + A + B + Select, then press Reset, Now, you will be invulnerable in fighting sequences during the game.
Sound test
At the title screen, press A + B. If done right, the cursor will disappear. Now you can press B to hear the sound effects and A to hear the music.