CSA0824: Exit to check for updates on the game to see if there's an update patch or DLC.
Looks like there's two DLC stories, which are free because the creators have words to say about the other kind. Words like "D"LC and money-grubbing. Or the kind of words Carroll is specifically forbidden from saying.
The first one seems kinda neat, and looks like you could start playing it any time. The way they're hiding Mima's last name is kinda cheap and dumb there. Is that the Scarlet Devil Mansion?
It seems you can only play the second one after you've beaten Cottagesnagged. Looks like older versions of the kids you've got already, but who's ... oh right, Shanghai used Alice's "doll enlargement project" to make herself full-sized at some point, didn't she? You have no idea why they're standing in Yukari's boundary-background from Immaterial and Missing Power.
You experience vast sorrow because this page is basically directly referencing the fact that this will be my last Touhou fanwork ever, given that I'll never be able to finish all the other ones.