I know it's a rare sight these days, but still I would hope such a release on GOG to have some gorgeous wallpapers and avatars accompanying it.

You may like Owlboy's presskit, as it has GIFs, mockups, portraits that can be used as avatars, screenshots that go all the way up to 4K that would look nice as wallpapers, and a few huge actual wallpapers:

http://www.dpadstudio.com/presskitOwlboy.html

Direct link (53MB):

http://www.dpadstudio.com/presskitOwlboy.zip