Pause the game and press A and LEFT together, then B, B, A, then A and RIGHT together, then B, B, A. Unpause and you'll be greeted by a picture of the development team with the sound byte "Cheater" then be in cheat or debug mode. Confirmed to work on Virtual Console version.
End Game
Pause and press: A + C, A + C, A + C, A, B, C, B, A.
Energy Replenish
Pause the game and press: A + C, B, B, C, C, C, A, B.
Extra Life
Pause and enter the following: A + Up, B, A, C, A, A, C, B.
Extra Life
At any time, pause the game and press B and Up simultaneously, then press B, A, C, A, A, A, A. You will hear Earthworm Jim say ''Cheater! Wheee Doggy!.'' When you unpause the game, you will see that you now have an extra life. You can perform this code as many times as you want.
Full Ammunition
Pause game play and press A + C, A, B, C, B, C, A, C(2).
Full Energy
Pause game play and press A + C, B(2), C(3), A, B.
Groucho Marx
Pause the game and enter: A, A, A, A, A, A, B, C.
Homing Missle
Pause game play and press Right + A, A(2), B, A, C, B, A.
Invincibility
Pause the game and press: A + B, A + B, C, A, Right, Right, Left, Right.
Last Stage Password
Buttville pasword on the Difficult setting. Redball, Cow, Atom, Atom, Cow.
Level Select
Pause game play and enter one of the following codes to start game play at the corresponding level.
Level Password
What the Heck? Press A, Right, A, C(2), Left, Right, A.
Snowman Press Right(3), A, C, Left, Right, B.
Evil the Cat Press Up, Down, Right, C(2), Left, Right, B.
Big Bruty Press C(3), Left(3), Right(2).
Down the Tubes Press Up, Down, Left(2), Up(3), Down.
Tube Race Press Up(2), Left(2), Down, Left, Up, C.
Snot a Problem Press C, B, C, Right(2), Left, A, B.
Snot a Problem 2 Press Up, B, C, Down(3), A, C.
Snot a Problem 3 Press A, Up, C, Up(2), Down, C, A.
Lab Press A, B(2), Down, Right(2), Left, Right.
Chicken Plummets Press A, B, C, Up, Down(3), Right.
Naked and Lovin' It Press C, A, C, Left, Right, Up, Down, Right.
For Pete's Sake Press A, B, C, A, B, A, Down, Right.
Andy Asteroids Press A, Left, A, C(3), B(2).
Andy Asteroids 2 Press C, Down, A(2), Down, B(2), Down.
Andy Asteroids 3 Press A, Down, Left, A, C(2), A, B.
Andy Asteroids 4 Press A, Down, A(2), C(2), A, B.
Andy Asteroids 5 Press A, Left, A, C(2), Down, Up, A.
Andy Asteroids 6 Press A, Right, A(2), Right, B, Up, A.
Intestinal Distress Press C(2), A, Right, Left, Right, B(2).
Who Turned Out the Lights Press A + C, B, Up, Left, Right(2), Left(2).
Who Turned Out the Lights 2 Press A, B, Up, B, Left, Right, C, Up.
Who Turned Out the Lights 3 Press A, B, C, Up, Left, A, Right(2).
Who Turned Out the Lights 4 Press A, C, Up, Left, C, Right, Left, B.
Who Turned Out the Lights 5 Press C, B, Up, Down, Left, Right(2), Left.
Queen of Buttville Press A, C, Left, Right, B, Left(2).
Buttville Helicopter Press B(2), Down(2), A, Right(2), Down.
Psycrow Press C, B, Up, Down(2), Right, Down, Right.
Level Skip
Begin your game, take controller one and press START to pause at any point, Now press A, B, B, A, A+C, B+C, B+C, A+C. You'll skip to the next level.
Level Skip
Pause the game and enter: B, B, A, C, A + B, A + B, A + B, A + B.
Mick Jagger Lips
Pause the game and press: B, B, A, A, A, A, B, C.
One-Time Energy Refill
Pause the game and enter A, C, C, A, B, B, A, C.
Plasma Weapon
Pause game play and press C + Up, A(2), C, A, B, C(2).
Red Afro
Pause the game and press: C, A, A, A, A, B, C.
Refill the plasma gun
At any time, pause the game and press C and Down simultaneously, then press A, B, C, A, B, A, C. You will hear Earthworm Jim say ''Cheater! Plasma!.'' Now when you unpause the game, you will have nine plasma shots. You can do this as much as you want.
Skip to Level 2
When playing the first level, pause the game and press, L, R, A, B, C, L, R, A.
Skip to the end of the game
Pause the game, and press A+C, A+B, C, C, B, B, A, A. You will hear Earthworm Jim yell ''Cheater'' and you will be brought to the ending scene of the game.
Various Codes
Press START to pause then enter one of the following codes:
Earn one continue: A, B+Left, A, B, A, B, C, A
Fill weapon to 1,000 rounds: A, B, B, B, C, A, C, C
One free guy: B, B, C, C, A, A, A, A
Plasma Shot Weapon: C, A, B, C, A, B, A, C
View Ending Sequence
Pause game play and press A + C, A + C, A + C, A, B, C, B, A.
View Map
Pause the game and press: A + B, C, C, C, A, B, B, B.
Weapon Replenish
Pause the game and enter: A + C, A, B, B, C, A, C, C.