Infinite Lives and Energy
During the game, press Start to pause. Then, enter Left, A, Z, Y, Down, A, Y, Down to increase your energy. Then, ener Y, A, Right, Down, Down, A, Left, Right to increase your lives.
Nine Lives
Pause gameplay and then press Y, A, Right, Down, Down, A, Left, Right.
Mega Plasma Gun
Pause the game and Press C, A, Right, Right, Up, Down, Up, Left.
3-Finger Gun
Pause the game and Press Down, A, Up, B, Right, Right, C, Right.
Homing Missle Gun
Pause the game and Press Y, A, Up, X, C, Left, Y, Up.
Barn Blaster
Pause the game and Press Y, A, X, Up, Right, Right, Left, Up.