The only hint for a publisher is the name Tom Werneck under the rules for Barbacan.
The cardboard box is printed to resemble wood.
The side of the box has the production code "Title Nr. 96969" on it.
In addition to Reversi and Barbacan, one side bears the French name Barbacane.
The inner lid of the box has short descriptions for the games in German, French, Portugese and Dutch. The backside of the box gives some example sketches with only German descriptions.
As I found the game on a flea market, there might be missing rules in the other languages beside German.