I thought I'd make a point that Hotline Miami has a comic book that is available as a separate product on GOG and was gifted for free previously even to people that don't own the game, so GOG seems to have the technology to add non-game, non-movie content to people's accounts which have no dependency on owning a base product.
Copy and paste the code, then run sed over it with s/comic book/OST/. A lick of paint and new license plates and here we are, sunny times!
Slauncha! (sp?)
fables22: If, by any chance, you've bought the game with the OSTs included and DON'T get your OST in the next couple days, please let me know so we can fix this!
I never got any separate OST products for these games added to my account but I just checked and 1 and 4 still contain the OST in MP3 format in bonus goodies for me. No idea if that is intended or not, just throwing it out here as a data point.