Full energy:
Pause the game and press Left, A, Z, Y, Down, A, Y, Down.

Nine lives:
Pause the game and press Y, A, Right, Down(2), A, Left, Right.

Plasma gun:
Pause the game and press C, A, Right(2), Up, Down, Up, Left.

Three-Finger gun:
Pause the game and press Down, A, Up, B, Right(2), C, Right.

Homing missiles:
Pause the game and press Y, A, Up, X, C, Left, Y, Up.

Machine gun ammunition:
Pause the game and press A, Up, Down, Right(2), Left, X, C.

Nuke-gun amunition:
Pause the game and press Y, A, X, Up, Right(2), Left, Up.

Normal difficulty passwords:

Level	Password
2	Gun, Energy, Blue Gun, Sandwich, Can Worms
3	Bubble Gun, Sandwich, Sandwich, Bubble Gun, Energy
4	3 Gun, Gun, Missile Gun, 3 Gun, Blue Gun
5	Energy, Bubble Gun, Bullet, Can Worms, Jim
6	Bullet, Sandwich, Gun, Jim, Gun
7	Missile Gun, Blue Gun, Bubble Gun, Bullet, Sandwich
8	Blue Gun, Can Worms, Bullet, Missile Gun, Jim
9	Bullet, Gun, Missile Gun, Bullet, Jim
10	Sandwich, Gun, Jim, Blue Gun, Blue Gun
11	3 Gun, Bullet, Bubble Gun, Energy, Bubble Gun
12	Missile Gun, Energy, Bullet, Energy, Energy