is because DirectX11 no exist 3D geometry.
2d is playable, but not comparable to Metro 2033 with 3d geometry in directx9 mode.
Metro 2033 with DX9 was better experience for me.
even renaming .exe original LL metro DXHRDC.exe, despite 3d vorpx options menu appears, geometry 3d does not work well in DirectX11.
we can make comparison with 2033 meter 3d geometry DX9.
Today I am trying to run Metro Original ll DX9 and metro redux DX9 with vorpx, but for now I have no luck with either.
I have all the versions on steam valve platform.