Ecco the Dolphin is a Wii Virtual Console game.

Unlock the Super Cheat options:
     Start  the  game  and  move  Ecco  right and left. Push the Start
button  to pause the game gameplay while Ecco is turning. Try to pause
the game when Ecco is directly facing you.
     When  you  do  that, press Right, B, C, B, C, Down, C, Up on your
controller.  If  you  done correctly, the cheat menu will appear. This
menu  contain  level  select  option,  message test option, sound test
option etc.

The Last Fight password: KNLMLMLC
The Last Fight Password (alternate): AJPPOWAX 
Undercaves Password: NVNAINCR

Level Passwords
The Undercaves: Enter "UYNAINCC" as a password 
The Undercaves 2: Enter "DQDIACCI" as a password 
The Vents: Enter "FKWLACCA" as a password

Level Passwords 2
The Lagoon: Enter "NDRBRIKR" as a password 
Ridge Water: Enter "HYAUGFLV" as a password 
Open Ocean: Enter "FNCQWBMT" as a password

Level Passwords 3
The Ice Zone: Enter "DWFFZBMV" as a password 
Hard Water Zone: Enter "QGDJRQLA" as a password 
Cold Water Zone: Enter "MCLFRQLW" as a password

Level Passwords 4
The Island Zone: Enter "UWXIOQLK" as a password 
Deep Water Zone: Enter "EILQOQLC" as a password 
The Marble Sea: Enter "XAKUQQLS" as a password

Level Passwords 5
The Library: Enter "FDGXQQLC" as a password 
Deep City: Enter "ZUVPQQLU" as a password 
City of Forever: Enter "AABBRQLU" as a password

Level Passwords 6
Jurassic Beach: Enter "PLABUNLT" as a password 
Pteranodon Pond: Enter "FQREUNLI" as a password 
Origin Beach: Enter "QXKIUNLX" as a password

Level Passwords 7
Trilobite Circle: Enter "OBEMUNLX" as a password 
Dark Water: Enter "JNXPUNLA" as a password 
Deep Water 2: Enter "WSGAKNLC" as a password

Level Passwords 8
City of Forever 2: Enter "ZBPIGPLD" as a password 
The Tube: Enter "KUVEKMLK" as a password 
The Machine: Enter "SDDBKMLG" as a password


Easy Passwords:
     You can conbine the letter A and letter N different sequences for
your password. You can unlock different levels.

Here's a list working of password combinations and the levels:

Passwords - Levels:
AAAAAAAA - Undercaves
AAAANNNN - Origin Beach
AAANNNNA - Welcome to The Machine
AANNAANN - The Vents
AANNANAN - Hard Water
AANNNNAA - Deep City
ANANAANN - The Vents
ANANANAN - Hard Water
ANNANNAA - Dark Water
NANANANA - Hard Water
NANANNAA - Dark Water
NNAANANA - Hard Water
NNAANNAA - Dark Water
NNNAAAAN - Undercaves
NNNAANAA - The Marble Sea
NNNNAAAA - Island Zone
NNNNNNNN - Welcome to The Machine

     All  other  combinations  will  not work, and will transport Ecco
back to the main title of the game.


Invincibility
     Enter a working password, then push the Start button and wait for
the  screen that shows the name of the current stage. Then, hold A and
Start.  Keep hold of A and Start until Ecco appears on the screen. Now
press Start to resume the game to become invincible.