How do you feel about Forsaken Doll?
Sorry for super late reply.
Forsaken doll is ok. I find the music in pofv in general to be really disapointing, if Zun's quality for the song was boosted like it is for the rest of the series in comparison (IMO) it might be quite good.
As it stands forsaken doll is *MUCH* tamer than Flan's theme. Flan's theme is weird and experimental, and is almost on the verge of being too chaotic to even be called music. Yet it IS music, I really enjoy it.
Forsaken doll doesn't really impress me with a melody that really seems to come across as gutsy, not at all.
I think liking Flan's theme also has to do with how you heard it for the first time. I first heard it when I was actually fighting flan for my first time. The music communicates "OMG IM SO FUCKED...But this is fun!" kinda. Which doesn't really make sense when you're just browsing some website listening to it as much. That impression also might not hit you as hard if you're already experienced with many Touhou games before actually reaching Flan.