Seaquest

Seaquest is a game released for the Atari 2600.

Gameplay
Your divers are out in the ocean collecting treasure; now that they have found what they're looking for, you need to pilot a submarine and return them safely to the surface! You can carry up to six divers at a time, and when you safely return the six divers to the surface, you move on to the next, faster level. Your sub has a limited supply of oxygen; if your oxygen meter gets too low, you will need to surface to replenish the oxygen supply. If you surface with less than six divers, you lose one of the divers. If you surface with no divers at all, then your sub will explode. To make your task more challenging, numerous giant sharks and enemy submarines travel throughout the waters and can destroy your sub on contact. To help out with these enemies, you have an unlimited supply of torpedoes which can be fired to destroy both the sharks and subs. As the levels progress, the game gets faster and more enemies appear at a time.