Fathom

Neptina, Neptune's daughter, has been imprisoned at the bottom of the sea by Titans. Your goal is to rescue her by locating the scattered pieces of a magical trident! You will need to take the form of a dolphin and a bird in order to locate the pieces that are hidden in the ocean and clouds. When flying in the air, there are several screens that have clouds flying by. Touch all of the clouds, and the trident piece appears! Other birds which are flying around will cause you to lose energy if you touch them accidentally. Underwater, trident pieces can be found by touching the sea horses. Octopuses, sharks, and a deadly maze of seaweed will get in your way and cause you to lose energy if caught! When you have located all of the trident pieces, the cage holding Neptina can be unlocked, but if you run out of energy first the game will be over.

Trivia:

Release the mermaid on level two, but swim up and leave before her cage fully opens. Transform into a seagull and fly to the left or right to a volcano. The initials of each programmer (Rob Fulop, Michael Becker and Wilfredo Aguilar) will replace the volcano fireballs.

The manual mentions to watch for a 'special surprise' for completing the game. At the end of level 7, 31001 95031 LGCA appears. This is actually Imagic’s old address (P.O. Box 31001, Laguna, CA 95031).

Imagic held a contest in which you could win $1000 by correctly answering how many tridents are hidden in the Fathom ad (below) and on the back of a Fathom box, and having your entry card drawn.