Please unlock the game in Germany.
The game is already rated by the USK and can be sold in Germany.

Edit1: I have contacted the devs in the Steam forums, they replied to me, that they will look into this issue and will get in contact with the GOG Team.

Edit 2: ok now it is available.

It's not blocked.

The game was not available to anyone, an error on GOGs side.

Try again.

Now it works, thanks!

Make sure to tell the devs :)

Already done :)