/vr/ - Retro Games

I'm playing a Doom 2 TC called Solace Dreams and I've got a really weird issue when trying to play the game at 4k.

There seems to be some darkening filter that's drawn over the image after everything else is rendered but it seems like the effect isn't actually tied to the resolution, its just a 1920*1080 translucent dark rectangle.

So it looks perfect at 1080p and below but going higher leaves you with part of the screen much darker than the rest and a distracting boundry where the effect ends.

Anyone any ideas how I would go about fixing this? The TC is abandonware and I don't think you can even download it anywhere anymore so I'm not getting help from the dev.

pic related how the game is supposed to look.