It is hard to put a specific genre on Grom. You have your thriller elements, crime aspects and some science fiction all in one. It is written with a generally good flow in the language, althought some times I stumbles across nuances that didn't really sound right.
Clearly a lot of research went a head of the writing, and you will meet a very interesting period in history, The book takes the reader to a lot of different places, and I really liked the idea with the Google Maps, where you can follow the characters.
The characters where well defined and people that you wanted to know better. At times their interactions where a bit over the top for my taste, but a author has the right to unleash his creativity in his books. The book contains a row of political opinions, that did not bother me. Pauls thoughts on Hillary Clinton was refreshing and made me think. You will also find some very explicit sexual scenes, but both subjects is clearly marked in the beginning of the relevant chapters.
All in all Grom is a very interesting debut, even if not all the parts were to my taste. I do however respect the authors work, and having read his next book I know he gets better.