Music also falls into similar key of setting the mood. Opening theme in StB is calm yet unsettling, it's meant to evoke both retro and youkai feel. There is sound added to most of it, either a downpour based on ZUN's comment or a static noise, if you want to tie it with the grain effect. Both possibilities reinforce feeling that you will be reminiscing in this game, just like Aya's portrait. DS's Newshound on the other hand is upbeat, full of anticipation that something will happen, but not to the point of nervousness. It's a fast-paced environment, but still Aya's (and yours) environment, so there is degree of control over it. I prefer Mysterious Note, but they both serve well in their respective games to set up tone. Wind Circulation is an easy-going piece that puts no pressure on you; good, because the pressure will start to appear very soon, but level 1 and 2 are easy even when you are beginner. It reminds me of wind blowing over empty fields, something of little purpose and surprise, despite being active. The Mystery in Your Town on the other hand feels like a cheerful, confident walk through bustling but not overcrowded city, continuation of the mood from Newshound. Even the more relaxed parts of it has this energetic beating in the background. I will add that for me this is the only track originally from DS I find better then its respective one from StB. Tengu Is Watching is probably the most intense track from StB, even above the later one, but still it isn't overwhelming. It feels pushy, but with a playful bend to it, a good representation of Aya bothering someone. Youkai Modern Colony is a track I don't like, it works as a standalone, but for me it gets bad when looped in actual gameplay. Which is somewhat surprising, because in a way it is the most StB-like track in all of DS, more of a happy drifting along than focused excitement, but it doesn't speak to me. Sleepless Night of the Eastern Country marks the moment when it starts to get really hard in StB, but instead of something more dramatic then Tengu is Watching, it turns out to be much more light-hearted and light-footed, with keyboard's sounds being the centerpiece. It perfectly sells the idea that for both Aya and boss all of this is just a fancy game, playing around. On the other hand, Nemesis's Stronghold, which enters in a similar moment gameplay-wise, is an actual escalation of dramatic tension. I would say that comparing those two highlights the most how StB atmosphere is "those are snapshots from place both fantastical and silly", while DS's atmosphere is "something is happening, pay attention!". This extends even to calmer Bell of Avīci, which while not as dramatic, still sets a focus-demanding mood, like if every beat and movement matters, which fits the difficulty at that point. It's absolutely amazing track, let that be clear, and yet I still prefer Retrospective Kyoto. It fits the gameplay slightly less, true. Instead, it's full of nostalgia, from the very first notes it feels as if you are entering an older place that still contains actual wonder, but there is more to it than just remembering, the main segment brings that old wonder to life, it shows that it still enjoys itself. Which somewhat ties to my next point.
IN is known, among other things, as the game that could have been the end of Touhou. It certainly has this feel at some moments. But StB, at least for me, feels as if it could've been such a closing game just as well. Imagine now, for a moment, following alternate history. The actual Touhou story, with some stakes in it, ends with IN. IaMP is there as a proof-of-a-concept that Touhou can sustain games outside of shmups, so that anyone wanting to do some doujin spin on it in the future won't feel too constricted to one genre. PoFV serves as a closing statement on personal level for returning characters, the incident is noted multiple times to not be dangerous, Eiki's judgement is always the highlight of the route and it gives both the crime and a possible, vague way to repent for given 2hu. Based on endings and Eiki's route some are faring better, some worse, but it isn't determined whether they succeed at repenting or not. PoFV gives each recurring character a new task, leaving to the fans what will they do with it in their own fanworks. The incident itself is about souls passing away and Gensokyo entering a completely new cycle, canon passes away to make room for doujin culture to create future. In this world, StB serves partially as a love letter, a realisation of a project ZUN had in mind since EoSD, partially as something like an appendix, bunch of final notes to those 2hus that weren't yet fleshed out enough, especially those that weren't around for PoFV or just appeared in it. Retrospective Kyoto becomes now almost a credit score for the story of Eastern Wonderland that is both full of nostalgia, but is also still alive in (you). No further Touhou games are produced by ZUN, instead he starts some new project.