Just got around to listening to the OST and analyzing it. Can only say it's apparent ZUN is getting lazier with each new release, the OSTs are becoming duller and duller. However he still has some good shit in him because I'm LOVING the 5th stage theme, and the 5th boss theme is my favorite of the bosses (though I barely like any others). The final boss theme is probably one of the worst in the series, but the extra boss theme is really nice. Nowhere near as epic as most of the previous extra boss themes but still good. And then 6th and extra stages I like as well. All the themes from stage 1 to 4 are pretty shitty and boring. Why does everyone love the 4th stage theme? It just sounds like a wannabe, more cheerful version of Makai Rural City Esoteria, my favorite theme in the whole series.
As for the characters, nothing exceptional other than, of course, Yukari 2.0. That's gonna be interesting with the consecutive game releases (if we ever get more appearance from the Sages) and the fandom~
Can't wait for some neat doujin remixes of this OST, there's barely any remixes of LoLK yet and they already have another Touhou to work on, lol.