Speaking to us in Paris, where he was promoting the 3DS-powered visitor's guide at the Louvre museum, Miyamoto did his best to maintain professional courtesy, but couldn't resist having a sly dig at Sony's new handheld.
"It's obviously a very hi-spec machine, and you can do lots of things with it," he said of Vita, which launched in Japan last December and in the west in late February. "But I don't really see the combination of software and hardware that really makes a very strong product."
Since a strong launch – it sold 325,000 units at launch in Japan, and 600,000 in its first few days on western shelves – Vita sales have slumped, particularly in Japan, where it has frequently been outsold by the ageing Wii and even its own predecessor, PSP.
3DS, however, has been Japan's best-selling hardware every single week since last August's price cut – and Miyamoto admits it was a lack of software that held back Nintendo's glasses-free 3D handheld.
"When we launched the 3DS hardware we didn't have Super Mario 3D Land, we didn't have Mario Kart 7, we didn't have Kid Icarus: Uprising," he said. "We were striving to have all of these ready for the launch, but we weren't able to deliver them at that time.
"We were kind of hoping that people would, nevertheless, buy into the product, find 3DS hardware promising, but looking back we have to say we realise the key software was missing when we launched the hardware."
In other words, Vita, like 3DS, needs games, and there are few owners of Sony's new handheld who would disagree with that sentiment. Despite a wide range of launch software, Vita releases since have been thin on the ground; the next big release for the system is Gravity Rush, due in the west in June.
Miyamoto's comments are extracts from an extensive interview in our new issue, E241, which should be with subscribers any day now and will be on sale on May 9. Other topics discussed include his surprising admiration for Angry Birds, and his desire to make a spiritual sequel to SNES classic The Legend Of Zelda: A Link To The Past.