Hello, I'm discovering the game right now (okay, I'm almost at the end of book 1), and it's quite fun (even if sometime a bit difficult for non-native English speaker) but I have several "technical" issues with it.
I play the native Linux version (did not tried though proton/wine) and playing on different computer (main computer + steam deck connected to TV).
I seems each time I switch (my savegames are on a SD card I move between the computers), the system.ngp1 file is more or less reset, so, I loose every achievements, card backgrounds and I _think_ some of the "spankbank" are also lost (maybe not related, but I know every one of them are not kept).
When I say reset, what it means is, I copy the file (or a backup of it), start the game, and then the file goes from i.e. 40kB to less than 3kB. Does anyone have seen the same, and better, know how to avoid it ? (bonus point to get back what I lost, but I guess I will have finished soon)
I don't know if it is related, but I never have seen anything in the "Memories" on the laptop, I can't even say if book1 as some content for it.
The other problem is more directed to
Droid Productions directly (if you see this). I guess you will not touch book1 and book2 anymore, but just to let you know, there is something not right with the sound initialization under Linux with it (I did not tried other builds). When the games are started, it does not use the "default" sound output, but the first in the list of devices, you must have changed something in book 3 because it looks like it works the way it is meant to be, there.
What it means is, i.e. if you connect the Steam Deck to a TV, the sound goes in the Deck speakers instead of the HDMI output (if/for those that have the same problem a workaround is to go in the Deck settings, change the sound output to "internal speaker" and then back to "default", but you have to do that each time the game is started. I've tried to find a config file somewhere to force it, the FMOD init but I'm unsuccessful right now). For the records, it is not limited to the Deck since my main computer does the same (but opposite, the HDMI output is first in list so it takes it instead of the sound card).
Also. just to let you know, the game is not verified (yet?) on the Deck, but it works wonderfully (the only other problem is the onscreen keyboard does not appear (for the few names input), but I can't say if the steam version does it). It could be better with gamepad input, but still very playable with mouse emulation (and I understand it way more work to add it, so no complains here)
If you're doing a straight VN with no side-content and no sprites it's one thing, but for a sandbox this was already far far more work than you can easily imagine 
