Mermaid Forest is a successful horror, creating suspense and intrigue. As with any horror, gore is to be expected and although the amount of blood certainly could have been cut down, it was in no way overdone. The characters are interesting and mysterious, with good and evil not as clear as it seems. The plot is more complex than just the common "search for immortality", the legend of the mermaids has a twist, making the story more interesting.

The subtitling is well-done, pleasant looking and not obstructing. The animation, even with the simple character designs, is beautiful and flows. Although it seemed odd to see Takahashi's typically comedic character designs in such a dramatic situation. The music fits well with the story, creating the right moods, blending in so well, you might forget its presence and just get wrapped up in the dramatic scenes. The ending music, playing during the credits isn't a special song that stands out, but it is sweet and pleasant, and the part of the chorus where each word is pronounced with pauses between them can get stuck in your head.

Unfortunately, there are some misunderstandings that the viewer might have if they have not already read A Mermaid Never Smiles, Takahashi's first installment to the Mermaid Saga. Such as Mana's apparent ignorance and rudeness; for example, at one point she asks Yuta "What is a cat?" While she seems stupid, Mana's ignorance comes from being imprisoned by mermaids for most of her life. She also comes off as rude during a dinner scene, but while imprisoned by the mermaids, she was waited on, so she is spoiled. These two points wouldn't make sense to a person unfamiliar with A Mermaid Never Smiles. Lastly, in the opening that takes place in 1936, where Yuta is shot by some people who look like soldiers, a little Japanese history comes into play. This was a military rebellion in Tokyo that was on February 26, 1936. The newspaper read that the Prime Minister died, which there were reports of even though he really didn't. Many political officials were shot that day (I don't know why they were after Yuta) This probably wouldn't make sense to most viewers.

All in all, a great horror story with some very decent elements, but some items remain confusing and unexplained to anyone who has not read parts of the original Manga series. Might also be very interesting for fans of Takahashi's other works as it is so different form her other works.