I'm not really impressed. Guard Duty has a lot of logical flaws,
the graphics are poor and the translation into German is faulty.
For me, other nonsensical text is now displayed at the same time
as the German text. There is no German voice output.
To be able to play the game on my Debian Linux system,
I downloaded ags_3.6.0.56_linux.tar.gz from
https://github.com/adventuregamestudio/ags/releases/latest
and unpacked the contents of the folder data into the directory game.
The files ags32 and ags64 have been replaced and the folders lib32,
lib64 and licenses have been replaced with all contained files.
Since then, the game has been started in full-screen mode
via the desktop link created by the installer. However, the game
won't stay on my computer for long.