Freebird Games recently released a Webcomic "To the Moon, too"
It's a sequel to the Game and free to read on [url]http://freebirdgames.com/de/to-the-moon-too_comic/[/url]

It's also available as DLC on Steam and as printed Comicbook on Freebird’s merch. store.

Enjoy the story. Do you think gog.com should sell such mini DLC stuff to?

Yeah. Im on your side. In this case i bought the OST on their website.
In the meanwhile i have seen other games that can be bought as "standard" or as "premium" edition, where the difference is the soundtrack.

dear gog.com crew: if you read this. Other people would be glad if you could complete your store with the OST for this game. :-)