The games (Soul Harvest and Fallen God at the least) refer to a Oktoberfest-themed DLC that unlocks special content (e.g. voices). Steam has it available as a free add-on. Is this anywhere on GOG? Has anyone contacted the developers about it?

Thank you for the quick answer.

It appears the Special Oktoberfest Map appears only on Soul Harvest, but both Soul Harvest and Fallen God recognize the customization options that appear after beating it (Bavarian advisor, brass intro theme and Bavarian flag holder). Also the intro changes! Pretty funny; sad that I don't know German.

nvm