All options
While the game is starting, press A,B,A,L,SHIFT A,Z.
Change Music And Stage
Up + FP - Spaceship (Glacius)
Up + MP - Jungle (Maya)
Up + QP - Castle (Sabrewulf)
Up + FK - Helipad (Orchid)
Up + MK - Museum (Fulgore)
Up + QK - Stonehenge (Tusk)
Down + FP - Street (TJ Combo)
Down + MP - Dungeon (Gargos)
Down + QP - Bridge (Jago)
Down + FK - Nothing
Down + QK - Dojo (Kim Wu)
Down + MK - Spinal Ship (Spinal)
More color
At the players select screen, press Z,B,A,Z,A,L.
Play like Gargos
At the players select screen, press Z,A,R,Z,A,B.
Sky stage
To have the special sky stage as a vs. level when you pick your characters, both players hold down then press down C to choose your character.
View High Scores Table
If you would like to view the high scores screen, just press Z. On the main screen.