https://bugs.winehq.org/show_bug.cgi?id=34014
--- Comment #19 from Adam Bolte abolte@systemsaviour.com --- I was able to test the videos in Knights of the Old Republic II using Wine 5.5 on Debian GNU/Linux 10 (Buster). Videos (including their audio) work fine.
A clean wineprefix was used. No winetricks commands were required.
Steam itself is very difficult and unpleasant to use to Steam's Library page not loading. I had to launch the wineprefix first using a build of wine-staging 5.4 I had previously installed, load the game under Steam, quit the game and Steam, then load it using 5.5 so the recent game was available from Steam's system tray launcher... (there's probably a better way that I couldn't be bothered looking up) but despite the Steam problems the game itself was just fine.