Hold L + R and select versus mode. Use the buttons on controller one during the match to play sound effects and allow clipping.
Play as Hiroshi Hase
Begin game play in feature mode and defeat Hiroshi Hase when he appears. His character will now be available in versus mode.
Secret Wrestler
To get the secret wrestler Hyper, play on hard difficulty, and get a full 200 points on your first two matches.
Sound Test
Hold L + R on controller two and select single player mode with controller one. Controller two may now be used to start various sounds during game play.