[Review contains spoilers]
The series has a slow start, seemingly with no major "goal" beyond Iblis' attempt to corrupt Ka-young. I kept going as 1) I love the main cast 2) Ka-young as a character was interesting; it's my first time seeing a consistently emotionless lead in what is marketed as a romcom.
The plot starts to truly unravel starting around episode 5, where we see relationships develop, and a clear emphasis on one's choice (wishes). Looking back, I feel there is freedom for interpretation for the viewer on whether a character's choice was "good" or "bad", "right" or "wrong". It instead focuses on cause and effect, which made the drama less dramatic in an annoying way.
The acting is superb, but there was a key moment in the story where I was unable to understand the narration about the tangerines and sorrow. I suppose it was a reference to a piece of content I've never heard of. The ending was also both sad and happy, depending on whose shoe you put yourself in. I would've liked more narration from villagers etc on Ka-young and Pan-geum.
As a romance, I'd give this 5/5 stars. Plotwise 3.75/5. Overall 4.25 stars. Recommended for those who can stick through a slow start.