NWR writes: "After the critical and financial success of Metroid Prime, Nintendo asked Retro Studios to craft a sequel. With far more freedom in creating the game, Retro's vision is more present than Nintendo's. Although Echoes had a two year development cycle, many ideas had to be scrapped in order to make the publisher's strict holiday 2004 release date. Among the deleted content was an unlockable port of Super Metroid."
