Reading the manga compared to the anime actually made this series feel a lot worse because of the weird things the author kept showing, such as child nudity and bodily fluids. You really start to notice these things and how most of the comic relief is... awkward sexual moments with the kids. Or at least body related things. If you can look past that there's still a lot of things that bugged me about the story itself that no one really mentions. As I read on I noticed it became more focused on shocking the readers without any real reason, for example they'd hit you with something messed up and it would always find some way to relate somehow in another messed up way. Just one "shocking" thing after another, always body horror related or leading up to something body horror related. It feels unnecessary a lot of times when the base of this story has a lot of potential. The recent arc (up to chapter 54) feels a lot like filler with the main goal lost and it really serves no purpose other than to give more shock material. Honestly if I wanted to read about body horror I'd just go read something by Junji Ito. It feels like that in the recent chapters sometimes but with kids and crazy emotions mixed in. There are many attempts to get feelings out of you for these kids and the horrible things that happen but a lot of it comes from them being kids and not actual character we care about. It was sad to see those parts yes but its definitely not that deep since it just gets more and more horrific. They hit you with too many emotional scenes and not enough build up to balance.

The art is nice yes, but it's really not enough to justify the rest of this manga. It is unique but it isn't a big factor for me in deciding what makes manga better or worse. Sometimes it was a bit hard to tell what was being drawn but its still very detailed and nice to look at.

I did find it interesting to see what was happening and to learn about the abyss but it definitely drags on a bit later and over time you just kind of expect it to be messed up all the same. 

The main characters are likable in how they have their own passion and love for each other, but I found a lot of problems with Riko especially. The decisions she makes are questionable and she really would be hopeless without the other two. It's like she gets into these difficult situations without knowing the consequences...even though it's pretty clear they are bad. She cannot sit still for even a second before getting into trouble again. Nanachi and Reg are the only characters I dont have much problem with because they do have some depth to them and they make logical decisions. I dont have a problem with the side characters either, its just that none of them are really given more depth. A lot of them are barely shown at all after being introduced (trying not to spoil). 

Overall I dont really get why everyone likes this so much, maybe its the creative ways to twist kids around and make things as gross as possible that hooks everyone. Maybe the emotional rollercoaster that just keeps going but never really hits. I would maybe understand their thoughts if they only read up to around where the anime stopped but that just shows how downhill it goes. It is interesting to go through but Im not really sure if I could say this was an enjoyable read with all these flaws. It does have its moments where you want to find out what happens next and it keeps you going until you realize that nothing really changes with the characters and the story just drags to shock you.