Turns out the latest version didn't work with S3 Virge, despite what i thought. The real issue is that i do not have an actual S3 Virge but i used 86box's S3 emulation. However as i discovered 86box did not implement fog at all and on a real S3 Virge the 3d rendering would be completely black. I realized that after i implemented fog in 86box and got a black screen and a friend of mine tried the game on his real S3 Virge. So i fixed fog in the D3D backend and confirmed it works with my friend's S3 Virge.

I uploaded a patch file - Petra099nS3VirgeFix.zip - which should fix the game for S3 Virge. The next version may also have a special S3D executable (S3D being S3 Virge's own API) too - the version almost works but there are a few glitches due to lack of 3D clipping (notice the triangles at the top left corner):