To be honest I wasn't expecting anything from this particular adaptation but I'm a fan of the manga so I was pretty intrigued regardless.

Time has shown us that adapting manga into live actions is overall a bad idea and can also be (this is too often the case) an insult to the original material and even to the fans.

Perhaps this is exactly the reason why "Parasyte : The Grey" is a breath of fresh air.
This live action is an adaptation but there is no Shinichi nor Migi here but Jeong Su-in and Heidi instead...

This is not intended to be an adaptation in live action of Kiseijuu this rather is a surprising live action adaptation that serves as a spinoff.
The story and characters are completely different but it still do in fact share the same premise and while it contains many similarities and references this adaptation is telling an original and new story.

So if you are generally afraid of adaptation in general (which is normal), in this particular case you shouldn't, the adaptation team did a very good job here, they made some strong and creative decisions to make the story more accessible while also exploring new and different themes but the core essence of the manga is well preserved and respected.

I was surprised by this adaptation it's an honest and humble proposition but it still manages to clearly demonstrate what both an adaptation and a spinoff should be.

Surprising.

8/10.