No 2560x1080 resolution.
And the picture is stretched, when 1920x1080 is chosen. Are we living in the middle ages or what?
going to refund in case there is no patch to solve this problem...

I'm about Sheltered 2

I don't know if it's the same in Sheltered 2, but you can manually set the resolution in Sheltered 1 with some undocumented commandline switches.

Either launch it from the Command Prompt with the following (as an example for 1280x960):
Sheltered.exe -screen-fullscreen 0 -screen-width 1280 -screen-height 960

Or just add this to the end of the "Target" section of the desktop shortcut:
-screen-fullscreen 0 -screen-width 1280 -screen-height 960

This only seems to work in windowed mode. No idea which resolutions are supported. Hopefully it helps someone.