I didn't read this particular collection, but every chapter is included elsewhere in "The Horror World of Ito Junji" series. I didn't want this to go without a review, so here we go.
Story, 4: While the premises are interesting, this collection chooses arguably the weakest chapters from their respective volumes and puts them all in one place. None are particularly gripping or frightening, though there is some dark comedy present in the "Kaiki Hikizuri Kyoudai" chapters (which fell flat for me).
Art, 7: Despite my grievances with the stories, the art is solid, as one would expect from Ito. There are some good biological horror pieces.
5: While the latter two chapters have a recurring cast, they all have extremely unclear motivations and backgrounds.
Enjoyment, 4: There are much better collections of Ito's work, and I don't really understand this particular collection's appeal.
Overall, 4: For those that have not read anything in "The Horror World of Ito Junji" collection, I don't think this is a very good introduction. I would urge readers to pick up "Tomie" or "Flesh-Colored Horror" as a starting point instead. There is certainly appeal in the chapters collected here, but the volume as a whole is fairly weak in my opinion.