The Metroid series has existed since 1986 and consists of plenty of games, including this year's Metroid Dread, but still has a rather nebulous backstory and history, especially as regards Metroid's race of bird-like aliens, the Chozo. Each game depicts events that are pertinent to the present day safety of the galaxy, but said events are largely a result of actions taken by the mysterious Chozo race sometime before the plot of the original Metroid.
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