Thread:Crowsoul50/@comment-33229352-20200116030855/@comment-33229352-20200121032858

Quote from the Wikipedia page:

"The game is set in 431 BC, four hundred years before the events of Assassin's Creed Origins. It recounts a secret fictional history set during the Peloponniesian War, which was fought between the city-states of Greece. The player takes on the role of a mercenary and is able to fight for the Delian League, led by Athens, or the Peloponniesian League, led by Sparta. The game's main storyline has the player character attempting to restore their fractured family after they and their siblings were thrown off a cliff in their youth and left for dead by their father by the command of the Spartan oracle. Parallel quest lines deal with the extirpation of a malign cult spanning the Greek world, and the discovery of artifacts and monsters from Atlantean times."

You can choose to play as either of the two siblings, Kassandra or Alexios. That choice doesn't change much, except the roles in certain plot points shift when you find the other sibling. You can make choices throughout the game, and they can majorly affect how things go. For instance, in the beginning of a game, there's a quest where a plague is going around your home island, and there are guards culling the sick. You have to decide whether or not you stop them from killing people who have the disease or not. I killed the guards instead of the sick people, and as a result the whole island is sick now because the disease spread.