Story: The first episode starts off as nothing spectacular, until the second half kicks in and the rethread of the first episode of the first season brings it up there. Way up there. The similarities and differences really sell it and as for the comedy, it keeps on coming. Every episode has "That one moment", from .gifs of dancing to more dancing and hilarious subs, to gratuitous English and "That's not a kick!", it rocks as a comedy, just like the first season.
Unlike the first, it doesn't slow down with serious moments that may feel like they drag. If something serious/plotty is going on, it'll make it funny. It may feel like slow progression, and it is, it's less on plot and more on comedy and hijinks, while keeping a few minutes for plots. I like it for that, and it has a fight every now and then to remind you there's violence and crap.
So comedy, comedic action, dramedy... and the after-credits, easily one of the best changes. One of the best. The ending was kinda... anticlimatic though, nothing special but it was funny. A pity it was cut short, but it leaves room for more volumes of the manga/light novel/original source to be translated into a third season.
Animation: Solid. Got the bounce, got the so adorable Eu and while hardly anything changed (If I can recall), it retains it's good looks. Props for facial expressions, glowy stuff, imagination spots and fan-service. The OP/EP recycle loads from the first season though, which is a bit of a bummer.
Sound: Per the norm, Eu has a different VO every episode, and it's still great. The addition of the Fairy is an ear full of rape when she's drunk, and she's drunk most of the time. Dreadful, absolutely dreadful. The OP/EP, can't complain, might have some deja vu, maybe, but still good.
Characters: We get more on Sarasvati and her... development... was well worth it. She has some of the best moments in the season. The others don't change too much, but we still get to see a bit more about them. This was just more of having them in fun situations working what they do best. Good stuff, and feels like the imagination spots have more impact this time around, working for Ayumu.
Overall: As a second season, it maintains just enough plot (Barely) for it to not warrant it being filler overall. While it may be short and not plotty, it's fun, funny and fan service abound. Just come for the comedy, that's why you watched the first season, right?