this may be specific to macos, but playing a song seems to open an mpv window that plays the audio track, is this by design?

thanks for this by the way, its is pretty cool!
it should be fixed by https://tangled.org/tsiry-sandratraina.com/fin/pulls/2 now
Thanks! Glad you like it 🙂
Yeah, that's currently expected. Right now Fin uses mpv for both audio and video, and on macOS mpv opens a window even for audio playback.
My plan is to replace audio playback with an integrated Symphonia-based audio player and keep mpv only for video. That should avoid the extra window for music while giving a better overall audio experience.