How to make Samus appear in Dead or Alive: Dimensions

The initial video of the Metroid: Other M stage in Dead or Alive: Dimensions showed a brief cameo appearance by Samus. Of course, it’s a well-known fact at this point that she isn’t playable, but you can bring her out for a power bomb explosion.

When playing in the Geothermal Power Plant stage (unlock it by completing the six courses in Arcade Mode), it seems as though blowing, whistling, or speaking into the microphone will bring Samus out for a brief moment. She’ll drop her bomb, and you’ll switch positions with your opponent.

Source