Is anyone else think it's making the murderers identity is too obvious

I'd never read the book and i had no idea about the story. my money was on Sam Neills character. I'd deduced (unsuccessfully) that he had used the kidney and liver to pretend he had his head cracked open, so i got how the murdered create his false death, but just the wrong man. His final words suggested that he was disappointed with life and that there was no escape from death. That lead me to believe he had lost someone important to him, perhaps enough reason for revenge. I did think also it could have been another person on the island. The director used the classic shot of a person in the shadows running past without the characters knowledge when the young woman was walking down the corridor, i thought it might be an indication but also knowing how the keys and codes of murder mysteries work i finally decided it was a red herring.

So in answer to your question, it wasnt obvious at all. Indeed if you had read the book or knew the story i cant imagine it would be possible to remove yourself from that knowledge of the killers identity and therefore the clues would be blindingly obvious.

Having forgotten the story, I presumed it was the Judge not on any of his traits, but because he was played by Charles dance.

____
It's me....Bara...it's always bloody Bara!

Have to disagree with you here. I didn't know the story (!) and I didn't think it was obvious who the murderer was, right uptil the end.

Well, I'm rarely able to figure out who done it in these kinds of films, and this was no different. Of course, I was really watching it to see Aidan Turner, but I did try to keep up with the plot. To me, it wasn't that obvious, but maybe if I had seen a bunch of these kinds of things and knew the genre a little better, it would have been. Of course, after it's all over, it becomes fairly evident who it was all along.

It was kind of (but then he died lol)
But not only because he was calm but because it was the only logical way one could connect all these people and their crimes. The judge or the cop were realistically the only two who could have known about all of it and collected enough information about the people involved.

Considering that there is another thread here where newcomers speculated whodunit (and came up with the wrong answer twice) it must not have been too obvious.

A lot of the audience must have known the identity of the murderer as soon as they had seen Charles Dance. An actor who typically plays villains.

I didn't know the story and I had no clue who the killer was. In fact, I thought they made it especially hard to figure out because of the way they made everyone look suspicious. Several different characters had close ups where they seemed to smirk and all of them were alone at different times with opportunity. So it really seemed like it could have been any of them while I was watching it.

I also wanted to point out one other thing, and I really don't mean to sound like a dick when I say this lol. Just some genuine food for thought.
You didn't like how "cliche" the outcome was, with the nice calm guy being the killer. But in order for something to get to the point where it's played out and overused, it had to originate from somewhere. And this story is pretty much where that came from. So it's not that this particular ending is cliche, but rather that this is what made that cliche scenario so popular to start with.