Successfully complete story mode with Wario on the normal, hard, or super hard difficulty setting without losing once. After defeating Rudy, you will battle Metal Mario. Defeat him without losing to unlock Metal Mario in "VS." modes. Note: Using the "Redo" option on the pause menu is counted as losing.

Successfully complete story mode with Dr. Mario on the normal, hard, or super hard difficulty setting without losing once. After defeating Rudy, you will battle Vampire Wario. Defeat him without losing to unlock Vampire Wario in "VS." modes. Note: Using the "Redo" option on the pause menu is counted as losing.

At the character selection screen in "VS." mode, highlight a character. Hold L and press A to increase the computer A.I. of that character one star to "Hard". Hold L and press B to increase the computer A.I. of that character two stars to "S.Hard".

Enter story mode and highlight the "Hard" selection. Press Z to change the difficulty setting to "S.Hard".