Nihon Review's Shadowmage writes: "Cynicism is in season with Humanity Has Declined. This highly unusual “comedy” about a UN mediator tackling the problems of a slowly crumbling society quietly pokes fun at the predictable idiosyncrasies of humans before suddenly shanking it with a deeply cynical joke. Instead of coating mankind’s fall from grace with drab grays and gothic blacks, this anime bursts forth bloomy colors complete with cute fairies sharply contrasting rainbows and sunshine with the fact that humanity has declined." (Anime, Jinrui wa Suitai Shimashita) 6/10