After defeating Mother Brain, Samus Aran discovers more of the deadly Metroid aliens on the planet Zebes, believed to be the aliens home planet. Now you, as Aran, must put an end to the alien threat by exploring Zebes and destroying the rest of the Metroid. While exploring the planet, you will encounter blocked passageways, but you will find upgrades that will allow you to explore the blocked areas later in the game. Along with new moves, new weapons are scattered throughout the planet, but they aren t necessary to finish the game. Depending on how well you play the game, you will get to see one of three different endings. Try to save the universe from the threat of the Metroid in METROID II: Return of Samus.