Sonic's Secrets: Earthworm Jim - Special Edition.
Free Energy Refill.

Press Start to pause the game then press:

A + C (together), B, B, C, C, C, A, B.

Jim will usually (but not always) call you a cheater if you entered the code correctly.

When you press Start to resume play you'll be back up to 100% energy!

 Free Homing Missiles.

Press Start to pause the game then press:

Right + A (together), A, A, B, A, C, B, A.

You'll hear Jim say "Cheater, Groovy!" if you
entered the code correctly.

When you press Start to resume play you'll have
eight shiny new homing missiles.
Invincibility.

Press Start to pause the game then press:

A + B, A + B, C, A, Right, Right, Left, Right.

Jim will usually (but not always) call you a cheater if you entered the code correctly.
When you press Start to resume play you'll be invincible!

 Level Skip.

Press Start to pause the game then press:

B, B, A, C, A + B, A + B, A + B, A + B.

Jim will usually (but not always) call you a cheater
if you entered the code correctly and you'll skip
ahead to the next level.
View map.

Press Start to pause the game then press:

A + B, C, C, C, A, B, B, B.

You can now use the D-Pad to scroll around
the level, pressing the A button will drop Jim off
and you can continue play from that point.
Level Codes

Press Start to pause the game then enter any of the following codes to jump to a different level.
Jim will usually (but not always) call you a cheater if you entered the code correctly.

 

Level Code
 What the Heck?

 A, Right, A, C, C, Left, Right, A.
 What the Heck? (part 2 - Snowman)

 Right, Right, Right, A, C, Left, Right, B.
 What the Heck? (part 3 - Evil the Cat)

 Up, Down, Right, C, C, Left, Right, B.
 Big Bruty

C, C, C, Left, Left, Left, Right, Right.
 Down the Tubes

 Up, Down, Left, Left, Up, Up, Up, Down.
 Tube Race

 Up, Up, Left, Left, Down, Left, Up, C.
 Snot a Problem round 1

 C, B, C, Right, Right, Left, A, B.
 Snot a Problem round 2

 Up, B, C, Down, Down, Down, A, C.
 Snot a Problem round 3

 A, Up, C, Up, Up, Down, C, A.
 Level 5 (the Lab)

 A, B, B, Down, Right, Right, Left, Right.
 Level 5 (Chicken Plummets)

 A, B, C, Up, Down, Down, Down, Right.
 Level 5 (Naked and Lovin' It)

 C, A, C, Left, Right, Up, Down, Right.
 For Pete's Sake!

 A, B, C, A, B, A, Down, Right.
 Andy Asteroids?

 A, Left, A, C, C, C, B, B.
 Andy Asteroids 2

 C, Down, A, A, Down, B, B, Down.
 Andy Asteroids 3

 A, Down, Left, A, C, C, A, B.
 Andy Asteroids 4

 A, Down, A, A, C, C, A, B.
 Andy Asteroids 5

 A, Left, A, C, C, Down, Up, A.
 Andy Asteroids 6

 A, Right, A, A, Right, B, Up, A.
 Psycrow

C, B, Up, Down, Down, Right, Down, Right.
 Intestinal Distress

C, C, A, Right, Left, Right, B, B.
 Who Turned Out the Light?

 A + C, B, Up, Left, Right, Right, Left, Left.
 Who Turned Out the Light 2

 A, B, Up, B, Left, Right, C, Up.
 Who Turned Out the Light 3

 A, B, C, Up, Left, A, Right, Right.
 Who Turned Out the Light 4

 A, C, Up, Left, C, Right, Left, B.
 Who Turned Out the Lights 5

C, B, Up, Down, Left, Right, Right, Left.
 Buttville Helicopter

B, B, Down, Down, A, Right, Right, Down.
 Buttville (Queen of Buttville)

 A, C, Left, Right, B, Left, Left, Down.

Fancy dress.

What's an intergalactic superhero to do, sometimes you just want to pop out to the shops without being recognised! To see some of Jim's favorite disguises press Start to pause the game then enter one of the following codes. Jim will usually (but not always) call you a cheater if you entered the code correctly.
 

Disguise Code

Funky Afro

B, A, A, A, A, A, B, C.

Ronald McDonald

C, A, A, A, A, A, B, C.

Joke Arrow

 Down + C, B, A, A, A, A, B, C. 

Groucho Marx

A, A, A, A, A, A, B, C.

Deely Boppers

B, C, A, A, A, A, B, C.

Big lips

B, B, A, A, A, A, B, C.

Novelty Glasses

A, B, A, A, A, A, B, C.

Cheat menu.

Press Start to pause the game then press:

A + B, C, C, A, A, B, B, B + C.

If you entered the code correctly Jim will call you a cheater and you will see a photograph of the Shiny Entertainment crew with the caption "Hey, Shiny crew only!". After a couple of seconds you will be taken to the cheat menu shown on the right.
View Ending.

Press Start to pause the game then press:

A + C, A + C, A + C, A, B, C, B, A.

Jim will usually (but not always) call you a cheater if you entered the code correctly.

All the above cheats have been checked, however the following cheats have NOT been verified, try these at your own risk!
Red5

Continue.

Press Start to pause the game then press:

Pause game play and press A + Down, A + Down, A + Left, A + Right, B, C(2), B + C.

Continue (alternate).

Press Start to pause the game then press:

Pause game play and press A + Right, B + Up, A, C(2), B, C, A. Note: This code may only be enabled once per game.

Extra life.

Press Start to pause the game then press:

Pause game play and press A + Up, B, A, C, A(2), C, B.

Extra life (alternate).

Press Start to pause the game then press:

Pause game play and press A, B, C(2), A(2), C, B. Note: This code may only be enabled once per game.

Energy Refill (alternate).

Press Start to pause the game then press:

Pause game play and press A, C, B, C, B, A(2), C. Note: This code may only be enabled once per game.

Full ammunition.

Press Start to pause the game then press:

Pause game play and press A + C, A, B, C, B, C, A, C(2).

Full ammunition (alternate).

Press Start to pause the game then press:

Pause game play and press A, B, C, B, C, A, C(2). Note: This code may only be enabled once per game.

Homing missiles (alternate).

Press Start to pause the game then press:

Pause game play and press A(2), C, B, A, C(3). Note: This code may only be enabled once per game.

Plasma weapon.

Press Start to pause the game then press:

Pause game play and press C + Up, A(2), C, A, B, C(2).

Plasma weapon (alternate).

Press Start to pause the game then press:

Pause game play and press C, A, B, C, A, B, C(2). Note: This code may only be enabled once per game.