By - DeXfiR
So, the files do exist inside the install folder on Steam, but they're in a format called ".usm". You'll have to look up some converter/extractor software to get it in a usable format. I did what you're doing some months ago and I remember it was annoying cause I had to extract the video and audio separately and then combine them afterwards.
They're all in (whatever your drive is )\steamapps\common\GOD EATER 3\resource\target\win\video. The opening is "MOV_DEMO_M_R_0000_os.usm" or "MOV_DEMO_M_R_0000_jp.usm". Hope that helps!
It worked! I've actually compiled 3 of these files into a video file already but they were some in-game scenes so i thought that it's a different kind of file. i was a bit stupid for not trying the "0000" file first...
Thank you so much!