Begin the game and move Ecco left and right. Press Start to pause the game while Ecco is turning. You have to pause it when Ecco is directly facing you. When you do that, press Right, B, C, B, C, Down, C, Up. If you did it right, a cheat menu that has options such as stage select, message test, sound test, and more, will appear.
Invincibility
Input a valid password, then press Start, and wait for the screen that shows the name of the level you're currently in with your password. Next, hold A and Start. Keep hold of A and Start until Ecco appears on the screen. Now press Start to unpause and you will be invincible.
Last Fight Password
AJPPOWAX is the password for this level
Level Passwords
The Undercaves: UYNAINCC
The Undercaves 2: DQDIACCI
The Vents: FKWLACCA
Level Passwords 2
The Lagoon: NDRBRIKR
Ridge Water: HYAUGFLV
Open Ocean: FNCQWBMT
Level Passwords 3
The Ice Zone: DWFFZBMV
Hard Water Zone: QGDJRQLA
Cold Water Zone: MCLFRQLW
Level Passwords 4
The Island Zone: UWXIOQLK
Deep Water Zone: EILQOQLC
The Marble Sea: XAKUQQLS
Level Passwords 5
The Library: FDGXQQLC
Deep City: ZUVPQQLU
City of Forever: AABBRQLU
