PS4 version of Yo-Kai Watch 4 includes new elements that will also be coming to Switch.
Yo-kai Watch franchise - Page - NintendObserver
Yo-kai Watch 4++ details multiplayer mode, new quests, and more new yo-kai - Gematsu
Yo-Kai Watch 4++ on PS4 Guide : New Features, Characters, and More
Yo-Kai Watch 4 - Opening Trailer Nintendo Switch HD
Yo-kai Watch 4++ details multiplayer mode, new quests, and more new yo-kai - Gematsu
Yo-Kai Watch 4 ++ Announced for PS4, Switch, Adds Online Co-op, New Maps and Characters
Yo-kai Watch 4++ - Improvements Trailer (JP) : r/NintendoSwitch
Yo-kai Watch 4++ details multiplayer mode, new quests, and more new yo-kai - Gematsu
Yo-kai Watch 4++ details multiplayer mode, new quests, and more new yo-kai - Gematsu
Yo-kai Watch 4++ details multiplayer mode, new quests, and more new yo-kai - Gematsu
Level 5 Yo-Kai Watch 4: We're Looking Up At The Same Sky (Bokura Wa Onaji Sora wo Miagete Iru) Nintendo Switch Regionfree Japanese Version Yokai Youkai: Video Games
Yokai Watch 4++ English Version on the Switch!!
Yokai Watch 4 ++ Save Game Editor for Nintendo Switch CFW