I play on PC and yes, I fully unpack all the files, and place it in it's own folder in my Games Folder.
Edit, as of 17/07/2023: Huh now it's working??? I has to restart my laptop for some updates, and then, on a whim, I opened up the game, and used the save file that was close to ending one, and the video played fine then. Maybe it was a problem on my part. In that case, I'm sorry for the trouble, and I greatly appreciate you translating this game~