The player is the Atlantis defense command, and their goal is to protect the cities of Atlantis from the invading Gorgon alien fleet. The Gorgon ships descend lower and lower until they're close enough to attack the cities with their laser beam, destroying an installation — unless you can destroy the Gorgons first. You have two cannons on either side of the screen that fire diagonally, plus a cannon in the center that fires straight up. In the Intellivision version, the central cannon is replaced by a flying saucer which can attack the Gorgons from the air, but can itself be destroyed.
In all versions, the game continues until the player has lost the final Atlantean city to the Gorgons.
This game provides examples of
- Difficulty by Acceleration: As the waves continue, the Gorgons attack with increasing speed, making them harder to stop.
- Earth-Shattering Kaboom: When Atlantis is completely destroyed, the world also looks that way as well.
- Endless Game: Atlantis is doomed, as the struggle against the Gorgons is a Hopeless War, and the waves (and the Gorgon fleets) will cycle until the player is defeated.
- Nice Day, Deadly Night: Each wave has a Day, Dusk, and Night phase. The latter is the hardest, as the darkness conceals the Gorgon ships, and you can see them only when they fly through your searchlights.
- Scoring Points: For destroying Gorgon fleet ships, and a bonus for every Atlantean city still standing at end of each wave.
- Sequel Hook: A single craft rises from the destruction of Atlantis, leading to the events of Cosmic Ark.
- Shout-Out: The name "Gorgons" comes from Greek Mythology, the most famous of which are Medusa and her sisters.
- Smart Bomb: Destroying the Gorgon Bandit Bomber also destroys all other ships on the screen at the same time.
