Since I updated to the newest Devuan (based on Debian) version, the game isn't launching anymore.
It's a matter of Dosbox being too old.
A quick/ugly fix is to install the newest dosbox and arandr:
> sudo apt install dosbox arandr
With arandr, save your desktop configuration (Layout/Save As..., save it as layout.sh in your sotc folder)
edit start.sh
> nano start.sh
replace dosbox command by dosbox -conf "dosbox_sotc.conf"
and then add the next line: ./layout.sh (don't forget to sudo chmod +x layout.sh)
Then edit dosbox_sotc.conf, at the end add:
[ipx]
ipx=false
[autoexec]
@echo off
cls
mount c "data"
mount d "data/CD" -t cdrom -label SHADOWCD
d:
cls
echo "shadow.exe instal.exe museum.exe"

And then when you doubleclick your shortcut, your dosbox will ask you to type one of these. And when you quit the game, the screen resolution will be good.

Note this is a very dirty fix, please GOG team, repackage the installer. Thanks