So, yeah that's basically it. The game starts in windowed mode and it's fully playable in its default 1280x720 mode, but whenever I try to change between resolutions or going fullscreen, it closes itself.

I found this - https://steamcommunity.com/app/253150/discussions/0/624075036387490743/

Windows: We experience some problems with fullscreen modes on high-dpi systems running Windows 8.1 when using desktop scaling of 125% or larger. As a known workaround you can:

Right-click on Halfway in the Steam library, select "Properties", then navigate to "Local Files" / "Browse Local Files"
In Windows Explorer, right-click on Halfway.exe, select "Properties".
In the "Compatibility" tab, check "Disable Display Scaling On High DPI Settings".

Just ignore steam part and find Halfway.exe, right-click on it and continue as above. ;)

Thanks for your help, but what I had to do is edit the settings.json file to make the game run in fullscreen from the start, and from then on I could change to whatever resolution I desired :D

Has the resolution crashing bug been fixed yet?

2021 and still, and it has mouse acceleration as well. This is basically unplayable unless you're used to playing 90's games with terrible software cursors and input lag.