That’s a tough one. Final Fantasy IX, maybe? There’s a love interest, but you’ll find that in almost every FF game. It’s more subtle in IX, though. If your kids can’t read, though, they won’t get much out of it unless you want to read out loud.
I know it isn’t on Switch, but just as a general response to anyone with the same train of thought, the Kingdom Hearts series is a great one for kids to watch. They won’t understand the story (because it is nonsensical gibberish) but they will enjoy just about everything else about it.