Press Up(2), Down(2), Left, Right, Left, Right, A + B at the title screen.
Defeat moth Boss
Pause game play and press B, A, B and A. The moth will fly away when the game is resumed.
Locate the falling drop claws, then crouch next to where they are landing. Face the claws and repeatedly punch in this direction. Each defeated claw will transform into a power-up. Use the pattern that the claws are falling to collect the heart, weapon bonus, or extra points before returning into position to hit more claws.