The anime is set in a world where God has abandoned the world and as such no one can reproduce or fully die. That is, unless a grave keeper puts them to rest. To be clear, people die but become... undead. As they lose their humanity they change into what could be seen more as zombies. However, the undead can live normal lives. If you are wondering, yes it does sound much like Dark Souls.
Probably the most impressive thing the show does is world building. Almost every reveal or aspect of the world that is being built is interesting and adds extra layers to the characters and themes.
One thing I will say is that the first half of the show is much more compelling than second. While a lot of the strengths of the world building and such are still there, the story archs are just not as interesting as the more philosophical elements are not as present later on. It might have to do also that the later episodes seem a lot more cliche and just toss a ton of characters at us instead of focusing on a couple.
It's interesting that Ai is really the only character I would call a main. She is extremely naive and self-righteous about things. To the point where she can become annoying. Each anime arch she meets characters that not only reveal aspects of the world to her but also new ideas that she has not thought about before.
The story is Ai's journey, and as such she has to move on from place to place. This causes some things to feel incomplete. The ending itself feels like a cop out, but is understandable. Surprisingly, some of the characters specific to each arch get more development than the more permanent side characters. There are also some instances where important plot points are not explained (mostly for sake of time.)
The art is stunning. Everything is well detailed and the use of shading and lighting are especially well done. The show is dark when it has to be dark and bright when it needs to be bright. The sound is also pretty good. While not as noticeable as the lighting the bgms are usually well placed and well chosen. Personally I think the OP and ED are good, but nothing to write home about.
The Sunday Without God has some amazing world building and the art quality to represent that. However, it seems like someone abandoned the show half way through as it turns into a bit of a mess of characters and unexplained plot.
