Thanks so much for checking out the game :3 So glad you had fun with it!
Yeeeeah, tbh, I have literally no idea what causes that bug, but I ran into it myself once or twice during testing, and it's a real bad one because sometimes it can end up showing random CGs as backgrounds when players haven't even encountered those CGs yet T_T It seems to resolve itself upon reloading again, but it doesn't stop it from randomly happening any time you load a save >.<" and once a spoiler has happened, it's happened :(
I can only imagine it was a weird bug with the version of Naninovel that I was using at the time I made the game because I remember I updated to the most recent version of the software at the time when I started the project, and as far as I know, the issue doesn't occur in older projects of mine where I've used older versions of Naninovel, or in newer projects where I've used newer versions of Naninovel, haha.
I'm just really really hoping that when I come back to this project to work on blue Blythe's route, that updating to the latest version of Naninovel will fix the bug! Because if not, I have literally no idea how to stop it from happening >.<"
But yeah, despite the stupid bug, I'm glad you enjoyed the game :D And hehe, it's a bit of a pain in the butt coding those extra silly lil things, but it's a lot of fun so it's worth it x3
Hope you get to have happy holidays!! :3