Unfortunately these suggestions didn't work.
There's no options menu displayed at all, just the cycling opening title screens. The game also does not go into mouse mode when I click the mouse buttons (my current mouse's wheel can't be clicked as a third mouse button or rotated, but I'm assuming that isn't the button I should press to get the mouse recognised.)
I tried looking for a text-readable configuration file & found "boot.config" in the "VekWars_Data" folder of the game. In this file I experimented changing "vr-enabled=" & hdr-display-enabled=" to every combination of "0" & "1" but this didn't achieve anything either.
I should mention I'm running VekWars on a PC using Windows 10 Pro.
(Btw, thanks for your assistance. I suspect ironing this out will help a lot of past & potential purchasers of your work.)