Looking at one of the stars through the glass ceiling of Dr. Carrington's office gives the message "A careful search brings you to the constellation known as Cetus, and the star known as Deneb Kaitos Ecoquestus". This works only in the diskette version of the game.
When Adam is inside the mouth of Cetus the whale, clicking the "walk" icon on the whale's throat gives the message "Adam doesn't need to go down the whale's throat. This is EcoQuest, not Pinocchio!".
When clicking the hand icon on the huge statue head, in which the flashlight fish is hiding, Delphineus says that works in some Sierra games, like Space Quest 3.
Adam finds a small cave with pirate skeleton and empty treasure chest in it. Talking to the skeleton gives the message: "Are you by any chance related to a guy named LeChuck?"