2004.1115 (NA), 2004.1126 (EU), 2005.0526 (JP)
Developer: Retro Studios
Publisher: Nintendo 
Metroid Prime 2: Echoes is a video game taking place within the Metroid series. It is a direct sequel to Metroid Prime. It was developed by Retro Studios and published by Nintendo for the Nintendo GameCube video game console. It was released on November 15, 2004. For the Japanese release, the game is called Metroid Prime 2: Dark Echoes.
<spoiler> The game takes place on the planet Aether, where an advanced race of moth-like creatures, the Luminoth, have been living off the natural energy of the planet, called the Light of Aether. A Phazon meteor struck the planet some 80 years previous, dividing the planet and its energy into light and dark dimensions. This new dark world is home to the Ing, a race of dark, liquid like creatures that can inhabit the bodies of the living and the dead. The Ing and Luminoth are locked in a bitter struggle for survival, as Aether's planetary energy cannot support both worlds. The Ing so far have been the victors, taking the energy from three of Light Aether's four temples. On top of this, the Space Pirates have invaded the planet, hoping to reap phazon lost in Tallon IV. A Galactic Federation Marine Corps ship was dispatched a week prior to the game, and contact with them was lost. Samus Aran has been sent into investigate, and meets and forms an alliance with U-Mos, the last of the Luminoth. She receives a container that will allow her to harvest all the energy from the temples on the dark side of the planet. By bringing the energy back, Samus can dissolve the Dark world into the Light world. Finally, a weakened Metroid Prime (creature), known as Dark Samus, is present on the world. It gains power by wearing a variant of Samus's Phazon Suit from Metroid Prime, which includes hugely upgraded, phazon-powered weapon capabilities. It seems to have no objective other than to absorb Phazon, and will destroy anything in its path. </spoiler>
The game features both single-player and multiplayer modes. Single-player is the primary focus of the game.
Metroid Prime 2: Echoes, like the first Metroid Prime, is a 3-D game in a first-person style. This was a large departure from the series, which had been previously all 2-D sidescrollers. However, Metroid Prime was largely regarded as being true to the basic tenets of the Metroid series, including focuses on exploration and platforming rather than combat. Metroid Prime 2: Echoes uses this same gameplay style as its predecessor, yet features a number of improvements and changes. Of these, the most dramatic is probably the existence of two parallel dimensions, Light and Dark Aether. Changes in one dimension often reflect changes in the other, a concept presumably inspired by games like The Legend of Zelda: A Link to the Past. While the maps themselves have the same basic layout, the rooms are often completely different, with new enemies and designs. Progress through the game requires that both dimensions be thoroughly explored. The atmosphere of the Dark World, however, is caustic and damages Samus' power suit, requiring the player to move between special "safe zones," at least initially.
There are more cutscenes than Metroid Prime, as well as characters that will talk to you through text displays, a first for the Metroid series. In some of the cutscenes there will also be text displays telling the story through the eyes of one of the cutscene's characters. Voice acting is limited to an invented alien language that will play at specific point in conversations with the Luminoth and briefs samples of English that are spoken by the Federation Troopers during select cutscenes.
Nintendo has made the curious decision not to convert the game into a PAL 50Hz mode for its European release. The game only supports a 60Hz PAL display, which is usually an option available in European game releases. As a result, the game will be unplayable or suffer from visual distortion (squashed, stretched, or rolling image) on televisions which do not support 60Hz modes. The game itself, and advertising, make this clear, although whether the average user will be aware of what the warning means is uncertain.
In the instruction manual for the game Nintendo claims it is to give a better gaming experience, as 60 Hz games are sharper. This is true; however, it is considered unusual for a console game not to support Europe's TV standard completely; the last major console title to be 60Hz-only was the Legend of Zelda: The Wind Waker bonus disk. It is speculated that the (often time-consuming) PAL50 conversion was omitted in order to have the game ready for the highly lucrative Christmas video game sales period, which the game's predecessor missed by several months.
Nintendo have not yet announced a PAL50 version for release a later date. However, given the tweaks to Metroid Prime for its Player's Choice re-release, it seems likely that a 50Hz mode will be available when Echoes makes its move to the budget range.
Morph Ball
Weapons
Visors
Platforming
Multi-Player