Mermaid's Scar has a fairly simple plot. Mermaids exist and eating their flesh either makes humans immortal or, far more likely, turns them into amphibious monsters. The story begins with two seemingly young people named Yuta and Mana heading to a new town on the same bus as a small child. At this town they hear rumours about the child's mother coming back from the dead and begin to suspect that she's eaten mermaid's flesh. But there are things going on that they can't predict. Things that could have dire consequences for both of them. The story is pretty well constructed and it feels complete, even though it's the middle of the series. The only real issues are that some of the twists don't make a lot of sense and the action isn't set up very well.
The characters are pretty flat. The majority of them have only a few personality traits, leaving them very flat. The only character who actually gets pretty fleshed out is the antagonist.
The art is dated and, unlike 3x3 eyes, it hasn't aged too well. The backgrounds are bland and the characters have very forgettable looks. It's not terrible, but it certainly doesn't have a distinctive or interesting look.
The voice work is okay. Yamadera Kouichi and Takaya Minami both do good jobs overall. The only problem is that they get overly melodramatic at times.
The yuri factor is a 1/10. This is another series where the female characters barely even interact with each other.
My final rating for Mermaid's Scar is a 5/10. The writing is good, but the flat characters, bland art and mediocre voice work all make for an average series. Honestly, if the concept sounds intriguing to you, I would check out the Manga instead. Is the full length anime any better? I haven't seen it so I can't judge. What I can say is that the Mermaid's Scar OVA is just average.
