Dolphin is an Atari 2600 game by Matthew Hubbard, published by Activision, in which players control a dolphin swimming through the ocean in a side scrolling view. In an effort to escape a pursuing octopus, players must listen to the sound effects from the game to determine where to swim. Walls of seahorses approach quickly, with very narrow gaps to swim through. The dolphins of the ocean squeak at the player to indicate where the gap is located, so the player can react in time. A high pitched tone means to swim high, and a low pitched ton means to swim low. With practice, it's a simple task to always know exactly where to swim in order to never lose speed. Each gap that is successfully passed without touching the sides earns a handful of points.
In addition to swimming through gaps, the player can use the currents of the ocean (represented by arrows in the water) to their advantage. Swimming over arrows pointing in the correct direction offer a speed boost, while arrows pointing the other way will reduce the player's speed. However, the currents of the sea affect the octopus too, so clever players will lure the octopus into the low speed currents and away from the high speed currents.
After a little while of swimming, the octopus will eventually change colors, letting players know that they have gone up a level. The octopus gets smarter as time goes on, and will start avoiding bad currents, making it harder to escape. Shortly after reaching the next level, a seagull will fly over the ocean. If the player can jump out of the water and catch the seagull, they will become temporarily invulnerable, granting the dolphin the power to defeat the mighty octopus for a huge haul of bonus points.
If the octopus got too close, players could give him "the slip" as a last resort by quickly turning around and swimming the other way. This could create some very tense and exciting moments
The "Friends of Dolphins" and "Secret Society of Dolphins"
Like many Activision games of the era, patches would be awarded to players who achieved certain scores within the game. They asked for a photo of the player's TV to determine eligibility. There were two tiers of patches that would be awarded for Dolphin players.
The first patch one could earn was the "Friends of Dolphins" patch. According to the game's manual, players would have to send a photo of a score of at least 80,000 in order to earn this patch.
But for those who could go even further beyond, there was the "Secret Society of Dolphins." The manual did not say what score would have to be achieved in order to join these prestigious ranks (though they did promise that it was less than 500,000). Once the magic number was reached, the score on screen would be replaced by a secret password which would have to be shown in the photo players submitted, and would allow one entry into the ranks of the Secret Society of Dolphins.
Atari 2600 Switches
The game featured eight game modes which allowed the player to start the game with higher octopus intelligence, or two player alternating modes. The difficulty switches change the amount of time the dolphin is invincible for after catching the seagull. On easy, it's four seconds. On Hard, it's only two. If the player is doing well and keeping their distance from the octopus, two seconds is not enough to turn around and catch the octopus before time is up, forcing players to deliberately slow down when the seagull is about to come.