https://bugs.winehq.org/show_bug.cgi?id=29521
--- Comment #36 from padraig padraig_mac@hotmail.com --- I initially had the main executable working after some messing with dlls without the hex edit (apart from the texture flip), but I'm not sure which dlls I used as I wasn't able to replicate it on a new wine prefix so then had to use one of the edited executables. I tried it another machine today and still have the texture flipping and again, required the edited exe.
My main laptop has an Nvidia graphics card but it is currently uninstalled so I should try it with that and see if that affects anything. I know there are issues with Nvidia cards on Window for Dark Omen.