EDIT: I redid the story part of my post since I felt it was a bit all over the place.
ZUN's Music Collection Vol. 1:
Hourai Ningyou ~ Dolls in Pseudo Paradise
(Alternate fan art. Despite being early Windows era, there's not much fanart. Most consistent artist would be Nekolina's comics featuring the two ladies from DiPP. Click for their Pixiv)
The Tracklist
(Categorized by music's origin)
Original Tracks
01. Legend of Hourai
04. Shanghai Alice of Meiji 17 (Original, 6 version is an arrange)
08. Forest of Dolls
13. The Strange Everyday Life of the Flying Shrine Maiden
Seihou 1
02. Dichromatic Lotus Butterfly ~ Red and White
07. Circus Reverie
Seihou 2
03. Lovely Mound of Cherry Blossoms ~ Japanese Flower
06. Enigmatic Doll
Touhou 1 Highly Responsive to Prayers
05. Eastern Strange Discourse
12. Eternal Shrine Maiden
Torte Le Magic
09. Witch of Love Potion
Touhou 3 Phantasmagoria of Dim.Dream
10. Reincarnation
Touhou 6 Embodiment of Scarlet Devil
11. U.N. Owen was Her?
Impressions
Music
I thought this was an okay soundtrack. I expected to like it more since I really love Seihou Kioh Gyoku and Embodiment of Scarlet Devil's soundtracks, and this seems to be from right around that period. My expectations were also high since it was seemingly taking tracks from HRtP, PoDD, EoSD and Seihou Kioh Gyoku, and those would be the exact soundtracks I would take from if I were in ZUN's position, since I LOVE the music from those games.
While there were some solid remixes (like Dichromatic Lotus Butterfly, Eastern Strange Discourse and Eternal Shrine Maiden) and Lovely Mound of Cherry Blossoms is an inspired choice, the soundtrack as a whole didn't really work for me (on its own; it was more interesting to listen to with the murder mystery in mind). I think it's the combo of weird picks (UN Owen was Her, Enigmatic Doll, Witch of Love Potion) and somewhat hit or miss original tracks combined with some lackluster remixes (I really don't like this mix of Reincarnation in particular).
Of the tracks I do like, I found Dichromatic Lotus Butterfly to be a really good track. It's a perfect track for representing Reimu (when she's in incident solving mode that is
) and I feel like Eastern Strange Discourse and Eternal Shrine Maiden are solid modernizations of the original tracks. As for Lovely Mound of Cherry Blossoms, I already loved the track and it seems to be pretty much intact.
Story
I mentioned it before, but the most interesting part of Dolls in Pseudo Paradise is its horror/murder mystery story. For the Honest Men mystery itself, I've read a lot of interesting opinions, theories and solutions (most of these I've linked to). Personally I'm okay with either a face-value reading of the mystery (a pierrot-youkai killing and eating the Honest Men) or the more common solution (one of the Honest Men became a youkai and killed the others). I think both readings still have a place in Touhou as we currently know it, partly because they don't seem to be contradicted by recent lore, mostly because they go into unexplored elements of Touhou's setting (either, the phenomena of outsiders failing to reach the Human Village and getting eaten by youkai or the youkai-ification process, since we know that human-turned-youkai exist in Gensokyo). I did have my own observations but to be honest, I don't really think there needs to or is any deeper reading than that. I also feel it's a bit too vague and silly at parts and I'm not really a fan of mysteries to begin with so meh
The only other thing I want to mention is the Alice theory. I initially was under the impression that the youkai was basically 100% Alice but after doing some extra readings, I think that's probably not the case. For me, it's really down to how ZUN's used Alice in the games; a lot of her early usage in the series is coming off to me as a case of convenience. ZUN needed a misleading character to obscure the main villains of PCB (
link), so Alice was brought back (despite ZUN originally intending a break in canon from the PC98 games). And since we know that PCB and IN were planned in conjunction with one another, and both Reimu and Marisa needed partners that weren't introduced out of nowhere (since I recall the original plan was to go EoSD to IN), Alice worked for that role (as Marisa's partner) too. With both of these in mind, it doesn't seem like much of a stretch that Alice probably inherited all of the symbolism from the character Dolls in Pseudo Paradise just for convenience's sake too (as in, it'd be easier to reuse/callback to those themes rather than come up with something from scratch again)... or maybe ZUN originally had a character in mind (Rin Satsuki anyone?) and didn't want all that work to go to waste. The point is really that while the connections are probably real and intentional, I don't think ZUN's intended for them to be used as proof of Alice being the killer in DiPP. I think at this point, ZUN probably considers them a bonus or leftover thing from when Touhou lore wasn't so well defined.
I don't think there's that much more to say. Like I said, I wanted to do an observations list but meh, I don't think the wheel needs to be reinvented here. I'm fairly satisfied with the most obvious solution because it's a means of exploring the darker side of Gensokyo that's hinted at, but never really explored in other official works. Overall, listening and reading DiPP was a pretty decent time killer. The mystery definitely helped to enhance what would have been a subpar listening experience, though the novelty of it is starting to wear thin on me. It would be interesting to see ZUN do something like this again, now that Touhou lore has been more heavily defined than when it was during DiPP's time, though I'm also perfectly fine with ZUN's presented the universe of Touhou so far too.
Extra Links
Touhou Wiki Translation
DiPP post on MoTK (has a bunch of stuff, like release history, corrections + other theories)
Kafka-Fuura Translation (referred to in one of the following analyses)
Drac32Drac's Analysis
Reddit DiPP Killer Theory
Swordianmaster's Analysis