Nepal, July 18 -- Players line up inside Nintendo's booth at a Japanese game fair to try upcoming Switch 2 titles, but, for once, the company's chirpy red-capped mascot Mario is nowhere to be seen.

The three games on display are all made by smaller-scale, independent developers seeking to impress users of the device that became the world's fastest-selling console after its launch last month.

But with Nintendo game sales long dominated by in-house franchises -- from "Super Mario" to "Donkey Kong" to "Animal Crossing" -- it can be hard for outsiders to break through.

"The Switch 2 has certainly gotten off to a strong start," said Krysta Yang of the Nintendo-focused Kit & Krysta Podcast.

But so far, "for third-party game creators, the su...