First pause the game. Then press A, B, A, B, A, Left, Right, Up, Down, Z to get to the battle against Grogh The Hellish.
Successfully complete the game using a memory pak. Then, start a new game to begin with the energy level from the game that was just completed.
Stand on the mushroom to face the scientist when first meeting him. Then, quickly press R, R, Analog-stick Up, Analog-stick Down, Up, Down, C-Up, C-Down, C-Left, C-Right, C-Up(2), C-Left(2), C-Right(2), C-Up(2), C-Down(2), Analog-stick Up, Analog-stick Down, Analog-stick Left, Analog-stick Right, Start to receive all special items.