I'm running into the same issue where the game doesn't load visuals properly. I'm using an AMD Radeon RX 6750 XT with 12GB of VRAM, so I’m well above the 1.5GB requirement. I also tried windowed mode and lowering the resolution as suggested, but nothing changed. Is it possible there is a specific compatibility issue with AMD cards?
Viewing post in Fazclaire's Underworld comments
Hi vizziggo. We had confirmed the game working on an AMD Radeon RX 570 that is well below the specs of your Radeon RX 6750 XT. So If the game just won't load you can try switching the graphics API form Vulkan to OpenGL by creating shortcut and adding this flag:
--rendering-driver opengl3
at the end of target section (outside the quotes if present).