I'm not sure if this has anything to do with the "newly" released April 2018 feature update for Windows 10 (I'm on the delayed update path), but the game will now crash to desktop after pressing Play Xenonauts in the launcher. I have already ran it as an admin, enabled w7 compatibility, disabled fullscreen optimizations, and re-installed.

When I saw "now" I mean that it has worked fine before, most notably before the update. I can't be sure it caused the problem, but it sure looks like it to me.

Can anybody offer any help?

It appears this was caused by Rivatuner having re-enabled itself, and conflicting with the DirectX 9 render.

Adding Xenonauts as a profile and disabling application detection for it seems to have solved the problem!