Never hoping the world comes to an end and that the religious nuts are wrong is wishful thinking. Personally I'd find a field of barley wheat and a good book on brewing then call it fair.
"Humanity Has Declined" threw me for numerous loops and I was pretty surprised with how good this turned out. I often find myself picking out titles that I am utterly disgusted with but this one was a good choice.
One of the first things that hooked me would have probably been the animation. The type of animation is extremely unorthodox and makes use of, cost effective everything. The characters and sets are fairly low budget but with such colorful work its hard to bash it. I found it amusing that the artists decided to represent the fairies, mouths hanging open and just a default smile no matter the mood. None of the characters really stuck out to me, typical this and typical that. The scenery and sets obviously are pretty much a color orgasm, throwing this and that maybe here and there.
As far as the actual characters go I felt a lot was missing about the main leads until the last couple of episodes. I would have thought in the end that the 2-3 inch little fairies would massacre the rest of humanity, and [Insert Bad Word] like rabbits and reproduce in an un-orderly fashion. The two characters I like the most were Watashi and Y, to me Y sounds like dumb name and probably something to call children 50 years from now. Her obsession with BL made me a little nervous probably because I expected to get flashed by a comic or some strange artwork. Watashi on the other hand, a smart girl who can cook an abundance of sweets might be the ideal "Waifu". The rest of the cast up until her school days were pretty much non existent or a bore. The other children at the school, in particular being the rose club probably gave me the willies. The different personalities of these girls ranged from farting tomboys to obsessive creepers, not people I'd like to be locked up with.
Now being a nano.ripe fan I give solely give credit to them doing the OP theme for watching this. The only time I've given music scores a thumbs up is for this group. After watching the opening a couple times I admit I tried dancing like the fairies and failed horribly. The ending theme probably didn't stick to me as much, I try and sit through those a few times but in general I avoid the extra minute.
The only real gripe I had with Humanity has declined would be the episode arrangement. I would recommend watching the last two episodes first so it has a degree of coherent sense. I was in the dark for the entire first half, everything was so episodical it felt like a stand alone. I tried to occupy myself by making sense of made up themes and propaganda such as sexism and governments. The propaganda probably came with the mention of the term "Commie" or communist and in the village Watashi has negative stimuli due to her field of work and general appearance. One of the minor or major themes, not sure which, would probably have been fairy society. Typical early humans referred to Gods and attempted to establish monarchies or different centralized governments. It was a little too much for me to wrap my head around in all honesty.
I definitely found myself in between the fence here. The concepts were good and I found it enjoyable in the end.
