If your mouse works on Steam games - then it's probably not your setup or PC.
It may be that Steam requires certain features before they'll release the game.
The Json file is normally only used to save certain data, so you probably can't make the game work by messing with that.
But it is possible that the games were not efficiently coded, or coded for machines with higher specs than yours, and so use up all the available memory which may cause it to freeze.
I checked on one of my games that's written in Unity - the mouse can move freely, but will do nothing unless you click on something, because I haven't coded mouse movements into the game (I have an onscreen joystick for touchscreen or keyboard controls).
You can test if on your machine if you want (it's free): https://evolutionarygames.itch.io/cloud-calming-3d (There are several layout options, you can select whichever you prefer)