I really enjoyed this VN, it's a heart-warming tale that deserves more attention from romance lovers! What stood out is that there are tense elements so it got an adventure feeling as well (the many locations you visit, the old-school RPG style ost).
From the interesting ocean lifeform lore to the coast/marine setting, you immediately pull in the audience by presenting the world via the POV of a curious mermaid. I found the character sprite to have a very unique artstyle and they're super expressive when it comes to emotions. Cordelia surprised blush face always cracks me up. Halora's sprite spooked me and her fate is so harrowing that instantly set off the tone that there's inherent darkness.
Cordelia is a super sweet fun MC and her choice options are quite suspenseful too, because it feels like danger is lurking at the corner every time she - as a newcomer - interacts with the human world. At the same time, it's humorous to read her interpretations of items in our world, such as how she describes a car.
I got the good ending at once and went back to get the bad ones. I have a soft spot for the overly terrible fate endings, haha. Ending 1 took me the most time to find it although I knew it had to do with the car sequence.
The romance is also interesting as there's a good build-up how Cordelia and Dunia get to learn each other better (and you as a player get to know more about their occupation, interests, et cetera), which makes it very easy to root for them. But you also can't help but wonder when Dunia sees through that Cordelia is a mermaid every time they hang out, and what would happen in that case.
Spoilers:
It gave me a shock when Dunia lashes out at Cordelia. I almost thought I landed on my first bad ending and couldn't tell where I made my mistake in choices. Luckily it's not. It made me so happy when Cordelia pretends to be a human and goes to the city to look for Dunia.
That line when Cordelia told Dunia that she forgot her wheelchair gave me a chuckle.
The finale is a meaningful emotional conclusion to both protagonists, and made me happy to see them reach to this point.