I have enjoyed the series, even it's is as predictable as engaging. The series is a mixture of different characters with the usual story aka serial killer script coming from famous movies. Looks like the director was inspired by movies like American Psycho, characters like Dr Loomies from Halloween or David Mills (Brad Pitt) from Seven. Everything is done in a Spaniard pretty acceptable way.
First, the series is not original but is quite entertaining from beginning till the end. So, overall the story is quite good. To add, looks like it is coming from a novel.
Second, if you have watched similar movies/series , the experience could have been far better with a more risky script. But to be honest, there is a twist I didn't see coming. Good for the writers.
Last, the scenarios, camera work, and acting are good. Also the Fx's too. The series looks serious, and not cheap as other Amazon productions.
So, overall an entertaining even predictable series if you have watched similar ones, but If you don't, the experience can be great. Enjoy.