These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Friendly Fandom: With In The Flesh. Both are about people who came back from the dead and try to be accepted, but with different approach.
Idiot Plot: By the end of the first season, though revenants have been identified as such by a great many people including the police, nobody has attempted to do a serious medical examination of one or to notify the outside world of their existence. Other specific examples: not placing a camera in the tunnel; not communicating in any meaningful way with the horde; not turning Victor over to the police when he appeared to be a normal (if quiet) lost child, presumably with distraught parents somewhere; not warning the town of an incoming long-term blackout. All decisions that should have been obvious to some or all of the people involved but somehow weren't, creating a lot of unnecessary mystery and suffering.
The Chris Carter Effect : Depends on which side of the fandom you're asking, but even those who believe the writers to have a planned mythology are cautious about their chances to obtain all the answers they want.
Values Dissonance : The sex scene int the first episode, between young LÚna and Frederic caused some major squick outside of France, regarding their age. The character is supposed to be 14, but looks much younger. That's why the twins will apparently get age-lifted in the American remake.
Squick : The rot which begins to infect the Revenants' bodies is bad enough to look at... But then Simon proceeds to EAT HIS OWN FLESH oh dear god...