Use the latest GE-Proton available (8-12 at the moment of writing).

Use Atlier Sync Fix to improve GPU performance -> https://github.com/TellowKrinkle/atelier-sync-fix/releases/tag/tkr-20230415 (extract d3d11.dll in the game installation folder and use the above launch option.

Fixes for missing audio on videos:

There are only 2 openings and 2 endings in video form, with subtitles, so it's not a deal breaker, but there are two ways to fix them: altering GE-Proton files or re-encoding the audio track of the 4 videos.

either 1. Altering GE-Proton files

As suggested in another report by user DaryKiri, you can rename or delete two libprotonmediaconverter.so files inside the GE-Proton install, however this "fix" is shared with all the other games using the same version of GE-Proton, with unpredictable side effects.

NOTE: in recent GE-Proton releases the folder structure mentioned by DaryKiri is no longer accurate (the gstreamer-1.0 directory was added apparently).

Rename or remove the following two files:

/home/<YOUR_USER>/.steam/steam/compatibilitytools.d/GE-Proton8-12/files/lib64/gstreamer-1.0/libprotonmediaconverter.so

/home/<YOUR_USER>/.steam/steam/compatibilitytools.d/GE-Proton8-12/files/lib/gstreamer-1.0/libprotonmediaconverter.so

Or 2. Re-encoding audio tracks

open a terminal window in the game's installation directory conaining movies (eg. steamapps/common/Atelier Marie Remake/Data/x64/) and type the following 8 commands:

mv Res_CMN/Movie/ending.wmv Res_CMN/Movie/ending.original

mv Res_CMN/Movie/ending_normal.wmv Res_CMN/Movie/ending_normal.original

mv Res_EN/Movie/opening.wmv Res_EN/Movie/opening.original

mv Res_EN/Movie/opening_2.wmv Res_EN/Movie/opening_2.original

ffmpeg -i Res_CMN/Movie/ending.original -acodec pcm_s16le -vcodec copy Res_CMN/Movie/ending.wmv

ffmpeg -i Res_CMN/Movie/ending_normal.original -acodec pcm_s16le -vcodec copy Res_CMN/Movie/ending_normal.wmv

ffmpeg -i Res_EN/Movie/opening.original -acodec pcm_s16le -vcodec copy Res_EN/Movie/opening.wmv

ffmpeg -i Res_EN/Movie/opening_2.original -acodec pcm_s16le -vcodec copy Res_EN/Movie/opening_2.wmv