I bought Democracy 3 (and both expansions) about a week or so ago. After some system changes, the game resolution options are gone.
I’m running Ubuntu 14.04LTS, on a Dell laptop (7537) and changed from the integrated Intel graphic chip, which was causing a rather annoying flashing windows issue with Democracy 3, to the NVidia GT 750M. (changing it is beyond the scope of this post, but a rather lengthy story)
My system does support lower resolutions than the 1920x1080 full screen, however, I prefer to play D3 in a windowed mode, and that is no longer available.
I’ve tried deleting the ~/Democracy3 folder (along with ~/.local/share/democracy3) and reinstalling, but to no avail.
BTW, the rather annoying window flashing is gone with the NVidia graphics card being used … so that’s a plus.