What is the name of the spin-off game that focuses on dungeon crawling?

The spin-off game that focuses on dungeon crawling is Yo-kai Watch Blasters.

Developed for the Nintendo 3DS by Level-5, Blasters grew out of the Blasters mini-game featured in Yo-kai Watch 2. Instead of controlling a human protagonist, players form teams of Yo-kai and take on missions, bosses, patrols, and cooperative challenges. Its action-oriented structure gives the game a stronger dungeon-crawling feel than the main role-playing series.

The Japanese releases use the name Yo-kai Watch Busters, with versions titled Red Cat Corps and White Dog Squad. International releases changed “Busters” to “Blasters,” partly because the game contains humorous references to the Ghostbusters franchise. That regional naming difference is the main source of confusion, but Yo-kai Watch Blasters is the canonical English title.

The game launched in Japan in 2015 and internationally in 2018. A free expansion, Moon Rabbit Crew, added new content, while the Japanese sequel Busters 2 was never officially localized into English.