Here are some cheats and tips for the game Ring King.
Invincibility:
Enter the “Training Gym” screen. Press A
on controller two, A, Select, A on controller
one, B on controller two, Select on controller one,
A, B on controller two, and B(2) on controller
one.
Final match:
Enter 92E8X2B6H2906A7XKC44S9 as a password.