Season 1 was one of 2019's standout shows, but Season 2 was a punching bag. It was outright hated by fans of the original manga and its 20 volumes and 181 chapters, normally enough material for ninety episodes.
Season 1 covered thirty-something chapters in 12 episodes.
Season 2 does the rest in 11 episodes. (Bizarrely, there's a special 12th episode... and it's all recap material, with nothing new.)
It omits entire arcs. It invents coincidences to get the characters from A to B, some of which are contrived. It strips away character material that explained why people did the things they did.
Personally, I quite liked it. (No, I haven't read the manga.)
Season 1 was set in an orphanage called Grace Field. Children were raised and cared for by a loving, ever-smiling "mother" called Isabella. Unfortunately, the place was a meat farm and the children were the produce. Season 2 is about what happened after their escape into an unknown world of man-eating demons.
Obviously, everything I say from now on only concerns the anime.
The first surprise is that the outside world isn't as dangerous as you'd think. Our heroes are hardly ever at risk of being eaten. The world's not divided into Heroic Humans and Evil Demons, but instead into oppressed vs. oppressors. Human collaborators are far more dangerous and active than any of the demons we meet, who tend to be either saviours or (at worst) a downtrodden underclass who aren't being allowed the human meat they need.
There's a demon aristocracy who run the child-eating system and for their own convenience have murdered anyone who threatened the status quo... but they're almost never seen in the anime.
Gradually, the story circles around to ask instead whether it's okay for the children to attempt genocide. This would have been a tougher question if it hadn't been for the magic SPOILER, but it's still pretty strong. (Especially given what we learn about the demons' biology.) Emma's an idealist. Will the story be generous enough to let her determination triumph, or will our heroes end up disappearing down a gullet? There's also the much darker question of what kind of human would actively support such a regime. The season doesn't really explore this directly, but it's hard not to think about. There's also what we learned about Isabella and Sister Krone in Season 1.
There are huge unanswered questions about the human world, incidentally. The demon world's medieval. They have some technology, but they're practically in the Middle Ages and they wouldn't last long in a serious fight. The human world, on the other hand, looks modern. The worlds diverged a thousand years ago. Why haven't they done anything? They could have crushed the demons. Personally, I'd be interested in a sequel that shines a light on the happily-ever-after Neverland. Might the humans have been selling arms to the demons, for instance? It seems unlikely that the demons developed all those guns and high technology by themselves.
There are stupidities, e.g. a certain person wandering alone into the town in ep.8. (Even if his plan had succeeded, he'd still have been going unprotected into a mob of starving man-eating beasts. If he'd visited a zoo, would he have climbed into the lions' enclosure?)
There's a long list of things that this Season 2 isn't. It's not action-packed. It doesn't have exciting demon-fighting. It doesn't have scary boo-hiss villains. It doesn't even have as much danger as you'd think. It certainly doesn't achieve the levels of tension that Season 1 did, although that's innate to the material. One of Season 2's biggest mistakes, in fact, was probably attempting to resemble Season 1 instead of just embracing a different direction and doing its own thing. (Its biggest, obviously, was cramming 60-odd episodes' worth of material into eleven.)
That said, though, I liked the moral debate. That's what the season's about, ultimately, so for me it worked. Even without the missing material, everyone's more than earned the right to their opinion, no matter how genocidal. There are extremists on both sides, with Emma's position being potentially terrifying. There are some successful emotional beats at the finale. I love the arrival of the SPOILERS, a certain character's parentage being left for us to infer and the two Emmas.
If you liked Season 1, though, you're probably better off reading the manga.
