Intelligent Systems is one of Nintendo's most decorated studios, responsible for major franchises including Fire Emblem and Paper Mario. However, based on leaked information revealing a variety of details about past Nintendo projects, Intelligent Systems may very well have taken an entirely different direction. The leak reveals that Intelligent Systems may once have been actively working on a Metroid project during Nintendo's Wii era, though the project was obviously canceled or never went into full production.
Little information about the project was revealed as part of the leaks, unfortunately. The project was simply listed as Metroid with no subtitle. Notes associated with the leak apparently say that the game would ultimately "release some time after Metroid Prime," which was re-released in Japan on the Wii in 2009. That obviously never happened, though what the plan was for Metroid, how far along its development was, and what led to its cancellation remain a mystery.
It's easy to look back at what Intelligent Systems was working on around the time, though. The studio was an active Wii supporter during its early years. Between 2006 and 2007, Intelligent Systems released both Fire Emblem: Radiant Dawn and Super Paper Mario, as well as WarioWare: Smooth Moves co-developed with Nintendo's SPD Group 1. Intelligent Systems notably didn't have another major Wii release, however, with five years passing before a new Fire Emblem and Paper Mario launching on 3DS.
Suffice to say, Intelligent Systems could have worked on a new Metroid game during this timeframe. It even makes sense that Intelligent Systems had more Wii projects in the works, especially after supporting the console so early. Perhaps Intelligent Systems tried to make a AAA 2D or 3D Metroid, struggled, and was ultimately shifted back to handheld game development.
Another notable detail about this window of time for Nintendo is that a new Metroid game really was eventually released for Wii. That game was Metroid: Other M, which launched in 2010, a year after Metroid Prime in Japan and Metroid Prime Trilogy worldwide. In other words, it's possible that Metroid: Other M was originally supposed to be Intelligent Systems' project. It's also possible that these notes put down the wrong developer and it should say Team Ninja.
A Metroid from Intelligent Systems isn't the only project included in the leak, however. It also talks about a Retro Studios action game starring Sheik from The Legend of Zelda: Ocarina of Time, a Dynasty Warriors-type game aimed at North American audiences named Project Hammer, and others. If only those initial plans for Zelda and Metroid had worked out as planned, who knows what Retro and Intelligent Systems would be working on now.
Source: ResetEra (via NintendoEverything)