Ecco the Dolphin 2

On Crystal Springs, normally you would need to find a song to break the rocks to complete the level. However, the entire task can be skipped, just swim inbetween the bottom two rocks and keep tapping B and C, and wobbling the directional pad and you will pass straight through.

To skip a large portion of Dark Sea, when you have opened the first spiked gate below the save point, enter the ship and head left then down. In this room should be an invincibility crystal. Go to the very the top right corner of this room, then quickly swim left using B and C, and you should pass straight through the wall. Once you pass through, quickly swim to the upper left of the screen to avoid being crushed.

When you have control of Ecco and can pause, Try to pause while Ecco is facing you. Once Ecco is facing you, press A, B, C, B, C, A, C, A, and B. If you entered the code correctly, a menu will pop up with all sorts of optionssuch as a sound test, level select, tempo, etc. This code can be entered as many times as you'd like, as long as the game is paused while Ecco is facing you.

Just entering the word easy mode in the password screen would work as a password. This difference it caused was it made certain lvl's much easier to complete like jumping certain spots in the game where you could easily lose in normal mode where no longer there. I am surprised no one ever thought about trying this code. I would always try and figure out codes and just enetered it one day when I was 12 years old. 16 years have passed and no one ever brought it up.

In the starting area break the two shells above you, and then swim through the tunnel to start the game in hard mode.

Crystal Springs = UEPMCVEB
Fault Zone = OZUNSKZA
Two Tides = KDKINTYA
Skyway = SZXHCLDB
Sky Tides = OZWIDLDB
Tube of Medusa = QSJRYHZA
Skylands = MULXRXEB
Fin To Feather = YCPAWEXA
Eagle's Bay = YCJPDNDB
Asterite's Cave = AOJRDZWA
Four Islands = UOYURFDB
Sea of Darkness = UQZWIIAB
Vents of Medusa = MMVSOPBB
Gateway = KDCGTAHB
Big Water = QQCQRDRA
Deep Ridge = UXQWJIZD
Hungry Ones = WBQHMIUE
Secret Cave = CHGTEYZE
Gravitorbox = UIXBGWXE
Globe Holder = SBFPWWJE
Dark Sea = MXURVMLA
Vortex Queen = OKIMTBPA
Home Bay = CSNCMRUA
Epilogue = CEWSXKPA
Fish City = SGTDYSPA
City of Forever = WSSXZKVA

Turn Ecco left or right and pause the game while Ecco is facing towards the screen. Press (A), (B), RIGHT, (A), (C), (A), DOWN, (A), (B), RIGHT, (A), and then unpause. You will now never die from lack of air or injuries.