It turns out that high-res mode in Feyna's Quest was broken. This is now fixed.
Improved full-screen scaling in Zynx. The game now disables texture filtering, disables OS-level scaling, and can scale by 50% increments.
So it turns out that the 32-bit Windows version of Feyna's Quest v3.0.0 is broken. I managed to track the error down to two libraries I'm using, the Opus audio codec and SDL. Using SDL_main's main function causes the program to hang when the next Opus sound effect is loaded. I don't know if the problem is a bug with either of these libraries or just a weird unexpected interaction between two. Anyway, the problem goes away if I use my own main function, so that's what I'm doing.
The new website now passes all security tests on the Mozilla Observatory.
Thanks to Let's Encrypt, the new website is now served over https.
The new website is now live and should work.