Really enjoyed this drama even though it's the typical mermaid story about growing legs when arriving on land, crying tears of pearl, etc. and some might think its cliché and boring but the lightheartedness, fluff and romance made it enjoyable. Liked how there was a killer involved and going after the ML and FL to add suspense or else the drama would've been boring imo.

What I liked:
- Spain trip in the beginning was a fresh start to the drama and I loved it a lot. Especially the chemistry b/w the leads was really good and just seeing them have a good time made it enjoyable.
- I saw some complaining about the side story or the parallel universe (Joseon Era) snippets were boring but I actually liked how they added that to the plot as it was something new and added substance to the plot
- I've watched Lee Min Ho's other dramas and have to say his acting in this one is the best. I like his character of being a conman having many talents while also being a kind person. He was able to portray the serious side of things while being witty and genuine. I liked how in the beginning of the Spain trip, he didn't withhold the typical "tsundere" character but kind of showed his fun and true self to Sim Cheong

What I didn't like:
- Their chemistry was somewhat lacking near the end, some of the scenes felt a bit like "funny awkward" to me
- Noticed that Jihyun's acting didn't have that spark like it did in the beginning and middle. It could be due to her character and her situation of having to return to the sea but her facial expressions came off a bit bland at the end
- Didn't like the idea of Sim Cheong erasing everyone's memory when having to return to the sea, it just seems hypocritical how she mentioned to Jun Jae that memories with the good people around you should not be erased but to be cherished so in a way it leaves this bittersweet feeling or the unanswered question of whether or not everyone remembered her in the end as it didn't show it at all
- Soon, the flashbacks or snippets of the Joseon era began to feel a bit boring as I expected what would happen next
- On the topic of memory, I personally think the power of erasing memories was flawed. It'd make sense if Sim Cheong erased parts of a characters memory that it'd totally be gone and not some temporary fix for a sticky situation. It irritated me how one would start to remember what was erased which was just a tactic to drag on some issues prolonging it
- Wished that there was at least one scene where Jun Jae actually witnesses her mermaid form in present day just to get like his reaction and everything but it never showed that

Overall, this drama is like True Beauty where the plot is cliché and you can expect the plot twists or events that happen next but they're enjoyable and lighthearted to watch. Also have to mention the writer also being a part of Crash Landing on You and how she did a good job with setting the mood for both CLOY and TLOTBS by incorporating the visually appealing places for us like Spain or Switzerland which really freshens up the dramas a bit and it was one of the factors that made me enjoy both dramas. I always put off TLOTBS but am glad I watched it as it was a good drama and is the best mermaid k-drama so far as I've watched others that were poorly executed.