Hey, I'm just leaving this here in case the devs take a look at the GOG forum. Just wanna say I'm really enjoying the game so far and I would definitely buy the Supporter Pack on GOG, should you ever decide to release it here.

I understand that there may be rights issues with publishing the soundtrack and artbook and that games published by HypeTrain typically don't sell their supporter packs outside of Steam anyways. But should you or your publisher ever reconsider, I'll be happy to give you more money :)

Seconded, I was going to put it on my wishlist, too.
Please vote for "Black Book - Supporter Pack" in the community wishlist.