I watched it over the past night and just finished the last two episodes tonight after work. It was a quick watch, and think it does hit atmosphere really well. Do think there are some spots when it's a bit uneven, especially when it goes full on anime with character cackling and reveals, but largely successful as a whole. Seems that Amazon has picked it up for a live action adaptation, but I'm unsure that'll ever come to pass as it has the feel of something that sits in development hell for a while, sort of how Death Note was with the US adaptation. It strikes a good balance between really bright scenes and dark ones, while also crafting a compelling world that made me interested to keep going, as was the case with Beastars earlier this year, which I also blasted through, and, like that one, I feel like I want to just read the manga now to see how the story goes. That said, I'm a bit more confident/excited about Beastars, while this has me apprehensive because this entire first season was all framed around the escape. Which made for a good arc and something to track, but that being the driving force, and the contained atmosphere of the house is what was compelling and intriguing about the show and the world. Taking out of that context, potentially, in further seasons and having the focus be on them finding other humans or training to rescue the remaining kids while working to topple the monster world feels like a sharp turn, if that's the direction it goes.
Suppose we shall see.