During his retirement announcement in 2026, producer Kensuke Tanabe revealed that the heavy focus on Sylux in the plot of Metroid Prime 4: Beyond was a longtime ambition of his, stating that the idea first came to him when developing the character during the making of Metroid Prime 3: Corruption and implementing early hints at the ends of that game and Metroid Prime: Federation Force. He wanted to make Metroid Prime 4 the start of a story arc revolving around Samus' conflict with Sylux, seeing that game as his last chance to do so on account of his age. Tanabe additionally stated that he wanted a later Metroid Prime game to focus on Samus realizing that she has to confront Sylux directly on account of his nature as "a dark, resentful villain who resorts to underhanded tactics," handing off the execution of that concept to his successor, Risa Tabata.

In an interview with Famitsu, an anonymous Nintendo spokesperson revealed that the inclusion of an open-world area was conceived during the first phase of development under Bandai Namco, based on the fan reception to The Legend of Zelda: Breath of the Wild. The spokesperson explained that both Nintendo and Bandai Namco struggled to balance open-world game design with the Metroid franchise's core focus of unlocking exploration by collecting power-ups, and thus limited it to the hub area of Sol Valley. Complications arose when Nintendo restarted development under Retro Studios (the developer of the previous mainline Metroid Prime games), as Retro lacked the infrastructure to make a new installment from the ground up and had to rely on what had already been completed by Bandai Namco. This meant that they were unable to adapt to the decline in popularity of open-world games and the rise of faster-paced first-person shooter and action titles during the 2020s. Additionally, the team worried that attempting to integrate these changing trends so far into development would disrupt the game's pacing. Consequently, the spokesperson described the game as being "pretty much divorced from the changing of times."