It is a trainwreck.
Breakdown: 2/10 story; 4/10 art; 1/10 character; 2/10 enjoyment; 2/10 overall.
There is a sub-genre of manga where the story largely takes a back seat, and very quickly devolves into a semi-nonsensical string of events that depict horrible, horrible, horrible, horrible things happening to people for no reason. Usually in this kind of manga guts and body parts start to fly and dismemberment is common. You know, those mangas, right?
This is one of those mangas.
The story starts with several students getting stranded on a strange island with a murderous madman. However, few chapters in it falls apart, and starts throwing weird plot ideas in, and quickly stops being believable, turning into some sort of grotesque nonsnesne where everybody chops everybody else into pieces, but somehow people have difficulty dying for good, despite all the horrific wounds they suffer.
Story is trashy, art starts out decen,t but gets worse. I think this is one of the cases where stop photos being used for backgrounds are noticeable, but by now I'm no longer sure. Characters are just nuts with no real motive, enjoyment is nonexistent, and overall it is quite bad.
The only reason I haven't rated it 1 is because I've actually seen few stories that were much worse. In this case, it looks like the author had some sort of story to tell, but ultimately failed.
Long story short, it is like one of those trashy horror movies nobody ever watches - with tons of fake blood, horribly shot scenes, and barely believable. Yet some people like watching those.
So, I'd recommend to avoid it unless this happens to be your thing.
Interestingly it turns out htat the author is responsible for other mangas in similar genre - Hokazono Masaya. He's the one that created "Pumpkin Night", which is among the worst I've seen.
From his other works, however, he participated in creation of "Akai Hon" where he collaboraed with someone else. "Akai Hon" wasn't completely horrible, only mediocre. "Insect Princess" looked like it might be onto something as well. So a good idea would be to check out those ones instead.
Overall if you his other works, you know what you get yourself into - horribly done horror with a lot of dismemberments. Occasionally this author produces mediocre and not "hrorible" work (like those Akai/Kuroi hon series), but this is not one of those titles.