Lords of Thunder

Boss mode:
Enter the configuration menu and set the difficulty level to "Hard", music to "01", sound to "01", then press Select + I. If desired, change the difficulty level back to "Normal" before leaving the menu. The Boss for the current stage will appear when game play is resumed.

10,000 crystals:
Enter the configuration menu and set the difficulty level to "Super", music to "02", sound to "02", then press Select + I.