Jack Mathews, former lead engineer who worked on the original Metroid Prime trilogy, criticized Sol Valley, the desert region in Metroid Prime 4: Beyond, as well as the motorcycle-like vehicle, Viola. He argued that Sol Valley diverted development resources without delivering sufficiently engaging gameplay. These are Mathews' personal views expressed in an interview with KIWI TALKZ, and do not represent official statements from Nintendo or the current development team.
Mathews stated that the game's other ecological regions continue the design approaches familiar to series fans, while Sol Valley feels like adding The Legend of Zelda: The Wind Waker-style open seas to a maze-centric The Legend of Zelda title. The area features wide-open vistas, with players primarily relying on large landmarks for navigation when heading toward their destinations.
According to Mathews, the team developed two or three sets of specialized AI and related technologies for Sol Valley, but these achievements were not reused in other areas. He therefore believes that this investment did not yield a sufficiently engaging exploration experience. Regarding Viola, he speculates that the team intended to introduce more relaxed traversal segments, even though the series already regulated pacing through non-combat exploration.
Mathews also acknowledged that introducing new systems into a sequel carries inherent risks, with the key lying in whether the development team can determine why the new mechanics are engaging. Game*Spark similarly noted that its review raised comparable concerns regarding route guidance and the non-linear experience in Sol Valley.