Hi Wormer,
I am too running Xenonauts at 2560x1440 resolution and have the same problems. There is however a thread about this here. I really hope the devs will implement a way of scaling the UI for those using a higher resolution.
Yeah, right now I get headache when looking on this tiny text (btw, my screens native resolution is 2560x1440). Hope the devs don't forget about those changes.