The anime is trying to do two things, be cool and be amusing. It's not trying to have a good plot or deep characters or anything like that. There's a good variety to how both of these are done though and there's a good balance of the two, so it works well in such a way there are a lot of fun and likable characters. For example, the various main characters have a cool edge to them in very different ways, and they also all have strange things about them that make them hilarious in different ways, the exception to the latter being Andou who is pretty much just pure bad ass, while the best example of both of those traits is Nomura, who is an incredibly unique protagonist and is pretty much just a steady stream of great one liners, both hilarious or cool, and crazy combat potential, which is also often accompanied by one liners. Some characters do get fleshed out somewhat with backgrounds and such, and there's even some decent character and relationship development, but its not really much in the focus and mostly just serves as a basis for Nomura to drop one liners and seem awesome. The exception to that is centered around the relationship between Nomura and Andou which has some more depth to it and serve as the finale for the season, though while it is probably the coolest of the anime's arcs the story is still only okay which shouldn't be surprising as story isn't really one of the anime's strengths.
A lot of why the anime is so cool is the action, which manages to be impressive in that its mostly grounded but has just a bit that goes beyond being realistic. This assertion may seem strange because all sorts of crazy stuff happens like fighting bears and because the entire setting is crazy with it being a normal school but people randomly carrying swords and getting into near death fights without getting in trouble, but with the tone and atmosphere that's what it ultimately felt like. There's also a steady stream of ability names appearing on screen with fancily stroked kanji which despite seeming dumb actually makes things feel more legitimate, though that's probably only because I don't know jack about actual swordsmanship or martial arts. So the action was cool and exciting. With that said, ultimately things did seem a bit simplistic in that each character only has one thing going for them, even Nomura who only really has one move.
The art style and animation was mostly decent in that designs and framing were good and there were some great scenes, but quality felt off at times. The anime also felt kind of cheap in that there were a lot of points that it felt that it was clearly padding for time which definitely hurt pacing, especially if you're marathoning it. The eye catches were well done. The OP was great both in terms of audio and visuals. The ED was decent enough in both. The soundtrack wasn't particularly memorable.
