I'll begin by saying I'm not a big fantasy reader, so I was a little hesitant to pick up the Pennymores but it never felt like heavy, high fantasy -- it had that 'fantasy elements' without needing to remember how to spell crazy names, complex magic, and keep referring to the map.
I'd seen some comparisons by other readers to books like Harry Potter, Narnia, or the Hobbit. And while those certainly are valid, I thought the characters were more like what you'd meet in Pixar movies and books like Encanto, Onward, Turning Red, etc. It was fast-paced in that way -- the characters weren't clique at all but had this real character feel that we love about those Pixar movies (I've noticed these movies have become more and more character-focused -- which this certainly lines with).
And that's what was great -- it was a fantasy world, without the complexity you sometimes feel in fantasy. It was more like a Pixar story wrapped in a magical, mystical setting, and that's what has made me a fan. Certainly quite the debut... anxious to see what's ahead for these Pennymores.