Ecco The Dolphin
Cheat mode:
Turn Ecco to the left or right. Pause game play when Ecco is facing the screen. Press Right, B, C, B, C, Down, C, Up. A cheat menu with level select, sound test, music tempo, message test, unlimited life, and teleporter coordinate options will appear. 


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Level Password 
Undercaves GMRIQDCM  
The Vents IUEINLDP  
The Lagoon GRTJZYJF  
Ridge Water OVDJDSLB  
Open Ocean GMYMDSLI  
Ice Zone GMBRHSLU 
Hard Water UKZFHSLS  
Cold Water SYQJHSLZ  
Open Ocean 2 CCVFFSLM  
Island Zone ALZBESLS  
Deep Water IHPFDSLP  
Volcanic Reef ADLYESLT  
Ship Grave SeaI NWUGSLU  
Wreck Trap WJHQGSLL  
Sea of Silence IZSXGSLF  
Deep Gate AKNBHSLI  
Marble Sea QSOMFSLQ  
The Library WBTXFSLV  
Deep City UNIQFSLN  
City of Forever WADUFSLB  
Jurassic Beach ONNBJPLY  
Pteranodon Pond WPVXIPLL  
Origin Beach AQZIJPLG  
Trilobite Circle GKGFJPLK  
Dark Water GZIUKPLR  
Deep Water 2 GAAGDPLP  
City of Forever YLQQZNLM  
The Tube MNEYELLB 
The Machine SKZNELLO  
The Last Fight KANZFLLX