This movie has a whimsical aspect similar to a children's tale. Actually, it is mostly a children's tale and will probably appeal to the whole family. I don't think it's appropriate to consider it with the same criterion as a rom/com aimed at adults. There is no implied magic, but the story resembles a magical tale. The story is funny in a whimsical way.

In some ways it is not a rom/com even though there is a whirlwind relationship between Flynn and Gwen. It doesn't get a lot of screen time so looking for chemistry here, or of selling the idea that the two fall in love just doesn't have a chance. The real relationship of interest is Zoe and Flynn. In a lot of ways Zoe is the star. Kiernan Shipka plays Zoe just the way she should. Not bad for a 11 year old actor if I calculate right.

The movie is similar to some other movies of the same genre. The identity of the real prince is a secret. The stranger becomes the kid's nanny. This situation plods along until the reveal which is like so many other movies where the person with the secret is just about to confess. And that creates a rift. The obligatory grand gesture is what you might expect if concocted by 2 children. All of this is predictable.

The story differs from anything believable in a myriad of ways, but it is a story for the whole family, not just adults.