Why are there only four wallpapers as free goodies?

Other online stores have much more for the same price: soundtrack, poster, 3 art cards, 5 wallpapers.

I'd like soundtrack!

I always choose GOG whenever possible as my platform of choice, except when we're getting treated as second-class citizens. This time I had to go with Humble simply because we get none of their cool extras (soundtrack, poster, art cards, etc.) and they even give you a Steam key (not that I like Steam, but they get updates much faster than any other platform, sadly).

I really felt bad having to buy elsewhere this time. I don't know why GOG couldn't have the same extras as the other DRM-free stores.

Agreed. I was pretty surprised that other places give you much more than wallpaper, there is a sale on one at the moment and you get


Soundtrack
Digital Poster
3 Digital Art Cards
5 Digital Wallpapers

Granted though, it is advertised as the Deluxe Edition. Maybe GOG can get this version as well eventually ?