The cutscenes were not working for me (TV static instead). None of the previously mentioned solutions worked. With Proton GE, the cutscens were showing up but there was no audio. The only thing that worked was installing WMP11 through protontricks. Just run the following command in the CLI after installing the game:

protontricks 204450 win7 wmp11

After this the game should work with Proton GE. If you get "command not found" message, make sure to add an alias for protontricks (or replace protontricks with "flatpak run com.github.Matoking.protontricks" in the previous command):

echo "alias protontricks='flatpak run com.github.Matoking.protontricks'" >> ~/.bashrc