When you mention Spelunker to someone they likely think you mean Spelunkey and got confused, but Square Enix has released its underground puzzle platform game in various guises in the past. In April it released Minna de Wai Wai! Spelunker at retail in Japan; now it's being localised to the West.
In the West it'll be called Spelunker Party!, riffing on the puzzle platformer's emphasis on co-op play - which was both online and offline in Japan. It's been confirmed for the Switch eShop and Steam with a new trailer, giving a release date of 19th October. [Update: The UK eShop shows that it'll cost £24.99 in the country]
As it's a rather short trailer, below is a longer video from the Japanese release.
Let us know if you plan to dig into this one on the Switch next month.