If I set my wrapper to use 4.10-staging and set nGlide to use Vulkan it breaks in the same way as you describe. I suggest just letting it use DirectX; the game is very undemanding and won't benefit from Vulkan anyway.
Thanks for the suggestion, it worked! With Glide set to DirectX (wind3d → OpenGL), and without dxvk (I enabled it for that prefix before), it started working fine.
I wonder though if there is some kind of radv bug, that's worth reporting that's triggered both by Glide/Vulkan and Glide/DirectX/dxvk/Vulkan paths.
I didn't try it with Mesa master though, so it could be fixed in newest radv. I'd need to get to building 32-bit Mesa through cross compilation. If it's broken too, I'll open a bug, but for now I'll just use winded3d path which works.
It could be also a Winevulkan bug though.