Let's begin with the pacing. An usual light novel based anime usually runs every four episodes equals out to a novel. Oregairu has three episodes equals a novel instead of four. Which is probably because most of the novel is probably just his beliefs. Now this is relevent because a majority of the show is just the him ranting about society.
Each episode usually concists of a single ark. So it's not like a lot is really happening it's more like things are happenings and he's just thinking. This is interesting since most light novel based anime they cute out most of the protaginist's thoughts. This also makes Hachiman one of the most developed characters.
As for the other character's I don't know. It's not like they're uninteresting, unrealistic, unrelatable, ect. It's more like you don't grow attached to them. Since most of the story is his thoughts you don't really get a lot of other character developement. Most of what you know of other character's is what Hachiman says. Besides that there's only really a few times you see them develope more. Basically it's enough to know who they are, but not enough to understand, or become attached.
One character that really stood out to me was Hayama Hayato. Who is basically Hachiman's oppisite. I liked how he spoke of idealism and while Hachiman voices his "realisim." Since most of the cast is either weak will, don't show up ofte, or are also loners I found it nice to see a different opinions in there... Though it usually lost...
Most of the shows art is plain, however Hachimans eyes... Well they describe him quite a bit. They look kinda lifeless, or tired, or maybe uninterested which really fits his personality. The animation for his flashbacks are also good since they're basically old film movies thingy. Voice actors are good. Hachiman VA captures his detest, and disinterest, while the other character's voice capture character's personality well.
The opening, and ending both really fit the show since they're slow paced, and mention isolations a lot. I know the ending song is called like "Hello, Hello Alone" just from that... Yeah. As for the BGM it's pretty fitting. Most of the BGM is almost like a rock and roll thing which plays whenever Hachiman thinkgs something, or talks about his beliefs. So like most of the show.
Now this show is probably geared towards intellectuals, pessimists, loners, those who enjoy dark humor, and romantic shows without a lot of romance. If you like shows based around simply crazy humor you probably shouldn't watch this. (check out Panty and Stocking, or Daily Life of Highschool Boys.) Also if your one of those Idealistic Masochist's watch it. You'll see your ideals crash, and burn...
