Twinkle Star Sprites

Highlight Load-Ran at the character select screen and press Down, Down, Down, Down, and A.

At the character select screen hilight Load-Ran, press UP four times and press a button to select Sprites or press DOWN four times and press a button to select Memory.
Alternatively, hilight Griffon (the 3-person group) and follow the instructions above to access Mevious (Up) or Dark-Ran (Down).

Highlight the character Griffon and press DOWN 4 times. Press a button and then you will be able to play as Dark-Ran.

To play as Mevious, highlight Griffon and press UP 4 times. Press a button and then you should be able to select Mevious.

At the character select screen highlight Load-Ran and press up 4 times. This will allow you to play as Sprites