You can change the brightness (gamma) on the image page of the vorpX menu.
The game is not officially supported, but with some luck you may find a user profile in the cloud.
If noone did a profile yet, you can try to create your own by making a copy of a profile that uses the same 3D engine. No guarantee that it will work, but worth a shot. If you don’t know which engine your game uses, check the game’s Wikipedia page. It might contain this info in the fact box.
If you have a basic profile working, you can then try to isolate the HUD and make it scalable using vorpX’s shader authoring tools.
Doing so requires basic understanding of how 3D games work. If you already have that or aren’t afraid to learn a bit, check the ‘User Profiles’ section in the vorpX help. The second part of this section explains briefly how to get started with shader authoring.