Metroid Prime 2: Echoes

Metroid Prime 2: Echoes (Metroid Prime 2: Dark Echoes in Japan and Korea) is the second Prime game in the Prime trilogy. It is a direct sequel to Metroid Prime, although chronologically, it occurs after Metroid Prime Hunters. It was developed by Retro Studios and published by Nintendo for the Nintendo GameCube. It is the first Metroid game to have a multiplayer feature.

Story
The game begins in Samus' Gunship traveling toward Aether, with a mission to rescue Galactic Federation troopers who had crashed onto the planet as well. As she enters the atmosphere, her ship is struck by lightning and the power fails. The Gunship is sent crashing onto the planet below, but regains power after crashing through the top of a cave. Samus begins the game with many of her abilities. While she is exploring the GF trooper's abandoned base of operations, however, she is sucked to Dark Aether after an encounter with a strange blue being that looks like her. There, vicious creatures, called Ing, attack her, and all her abilites besides her Morph Ball, Charge Beam, Power Beam, Combat Visor, Varia Suit, and Scan Visor are taken away.

Despite this, she continues her search of the GF trooper base, eventually finding their landing site, which has their burning ship, the G.F.S. Tyr, situated there. After watching their commanding officer's last entry log, she discovers all the trooper were brutally murdered by Dark Splinters. She moves on to investigate their deaths, but soon realizes she has reached the end of the line: the room she that might continue her path is blocked by some form of shielding that is impervious to her weapons systems. However, she finds a missile launcher near the landing site, and after a short battle with some Dark Splinters, continues to explore the Temple Grounds.

Samus eventually makes it to the Great Temple, where she battles a Dark Alpha Splinter and recovers a mysterious "Energy Transfer Module", which, as she finds out from an alien Luminoth called U-Mos, is the key to the Luminoth's victory over the Ing. U-Mos sends Samus to Agon Sector, where she must recover the first of the four Dark Aether energies.

Samus does so, exploring Agon and Dark Agon, as well as the Space Pirate complex contained within both. After recovering a Temple Key and recoving her Space Jump Boots, Aran infiltrates the Pirate Base, coming face to face with Dark Samus. Aran gains the Dark and Light Beams soon afterward, going once again to Dark Aether to recover the two remaining Dark Temple Keys. Once doing so, she destroys Amorbis and recovers the energy of Dark Agon.

Once she returns to the Great Temple, U-Mos gives her the mission of going to Torvus Sector and recovering the lost energy there. Samus complies, exploring Torvus, which has a lesser, but still prominent, degree of Space Pirate invasion. This time, Samus faces the Boost Guardian, the Grapple Guardian, and the Alpha Blogg while finding the three Dark Temple Keys and accessing Dark Torvus Temple. There, she fights the Chykka, obtaining the Dark Visor and the energy lost to Dark Torvus.

However, upon return to U-Mos, the great warrior tells her she has one more task: to go to Sanctuary Sector, a fortress high in the cliffs, where the last Energy Controller lies. There, Samus gains the last of her missing abilities, the Spider Ball and the Power Bomb, which she returns to Torvus to reobtain. She then fights Dark Samus one more time, acquiring the Echo Visor. Once she finds the Dark Temple keys, Samus faces Quadraxis, a Luminoth unit gone rogue, whom after defeating, acquires the Annihilator Beam and the third energy contoller - that of the Ing Hive.

When she goes back to U-Mos, he, with the power Aether now has thanks to her, gives her the Light Suit, a suit that actually has the Light of Aether within it. Then, he tells her the most dangerous mission she'd have to complete on Aether: to obtain the final Energy Controller, hidden within the Sky Temple. To enter the Sky Temple, though, she must find nine keys, two in Dark Agon, two in Dark Torvus, two in the Ing Hive, and three within the Sky Temple Grounds. With much difficulty and complex stratery, Samus finds these keys, and enters the Sky Temple.

Within the Sky Temple, Samus faces the Emperor, a mighty behemoth that rules the Ing Horde. Although she is almost defeated, Samus prevails, and obtains the final energy controller. Within the energy, Dark Aether starts to fall apart, and with only eight minutes, Samus races down to the Sky Temple gateway, where she confronts her old archnemesis - the Metroid Prime.

Dark Samus and our heroine duel out to the death, but Samus utilizes the Metroid Prime's deadly flaw - an overload of phazon. Sometimes, Dark Samus bursts out phazon blasts which Samus can collect with her Charge Beam and fire back at her. Once Samus does this continuously whilst watching out for the fiend's devilish attacks, she prevails. Although the Metroid Prime tries to touch Samus and take over her suit, she vanishes into small blue sparks before this could happen (again). Samus then quickly activates a portal conveniently placed right next to the Gateway, and, before Ing can kill her, jumps through and back into the real world.

The Luminoth, glad that they have their planet back, rejoice and thank Samus. Samus gives them back their equipment (the Light, Dark, and Annihilator Beams, the Dark and Echo Visors, and the Light and Dark Suits) and returns to her gunship, where she takes off and flies off, into the vast darkness of space.

However, after Samus leaves, Dark Samus reforms out of Phazon energy in space near Aether. This is continued on in Metroid Prime 3: Corruption.

Wii Version
At Nintendo's Fall Press Confrence in Japan it was revealed that Metroid Prime and Metroid Prime 2 were among a collection of Gamecube games being remade for the Wii platform and sold at budget prices called the Play it on Wii selections. The games will have new motion based controls and slightly improved graphics. There is no word on whether or not the games will be seen outside of Japan. Although based on the origanal game's sales in America it is safe to assume the U.S. will see them at some point. 

Trivia

 * Echoes is the first game in the series to have a multiplayer mode (though Metroid claimed to on its box art).
 * Although Echoes is the sequel to Metroid Prime, chronologically, it occurs after Metroid Prime Hunters.
 * The multiplayer track entitled "Hunters" is a remix of Super Metroid's Green Brinstar music. The flooded part of the Torvus Bog temple plays a remix of Super Metroid's "Red Brinstar" theme. Also, Metroid Prime 2's escape theme is a remix of the original Metroid's escape theme.
 * There is a minigame based on it in WarioWare: Smooth Moves.