I wanted to take some shots of the beautiful game as I made my way through but Prt Scr didn't appear to work as I've been unable to locate them. I've resorted to running non-steam games through that service just to use the convenient F12 auto-screenshot feature but am hoping to find a solution here as this affects other gog games. Cheers!

Well now, this is quite a few months old at this point, but unless a program specifically overrides it, all that the print screen button does is copy the screen to the clipboard. You then have to paste it in to an image editing program of your choice (like, say, Paint) and save it manually.

Or just use Steam, as you've done. Maybe Galaxy will get a similar function as well, in the future.