The introduction to the setting felt a bit like reading bullet points. I would've liked to find things out a bit more naturally as things happen, not by the narrator just listing them off. The plot is moving very fast at the beginning. I feel we didn't get to see enough of MC's original emotions to really feel the change of heart because of it. 
Meri and Aodhan act weird with each other. I can't figure out if they're close or not. They appear to be, but in the first scene he's mentioned,

it's because Meri is trying to avoid him. They talk about things you feel like best friends should already know about each other, but they act like best friends.

There are a few inconsistencies.

Like, when Meri says she left her phone to charge before she went out to the market (and ended up at the fish&chips and then at the beach), yet when she comes back home with Aodhan tomorrow, her phone is dead and she needs to plug it into a charger. She also has a very weird reaction to Aodhan texting her he might know where the key is. She just decided he's right and the key is there, and so that means everything is real. That was a bit of a jump.

Some of their adventures were a bit too easy. Like, no way that would really happen.

The first singing scene was very weird. Could've been written differently to make it seem more magical and less awkward.

A little past the halfway point, the characters grew on me, and the story really slowed down. This is the point where I really started liking the book. 
I was really rooting for them. Even though the start was rough, the characters and the story grew on me, and I'm excited to continue reading this series.

I received an advance review copy for free, and I am leaving this review voluntarily.