Mario + Rabbids: Sparks of Hope is a joint effort between Ubisoft and Nintendo, but Ubisoft is doing the brunt of the work. As shared before, Nintendo is doing a lot of the approvals on the project, but that doesn’t mean they aren’t involved in development as well. That even includes some input from Shigeru Miyamoto himself.
In an interview with NintendoEverything, Mario + Rabbids: Sparks of Hope producer Xavier Manzanares elaborated on Nintendo’s role in the game, and that included insight into what Miyamoto is taking on. With Nintendo in general, the company has taken on a largely advisory role. They’re making sure everything is in-line with their expectations and rules for the Mario universe. With Miyamoto in particular, he’s testing builds of the game as development continues.
It’s unclear how much feedback Miyamoto has given during the development process, but there’s no doubt his suggestions and comments have helped steer this sequel, just as they did with the original title.