Hey, I never played Dark Omen before so I am not sure how exactly it's supposed to look or function when working correctly. The game is running in 3D mode.
I got it working on Windows 10 by following the guide posted here and I noticed that when I pan the camera around the map the pixels on the screen do a shimmering effect (looks a bit like looking at the game trough TV static). This effect gets progressively worse as I zoom out the camera. If I don't there is no effect. Another way of describing it might be that it looks like an extreme form of aliasing.
I tried checking YouTube videos but the video compression is too bad to determine if the effect is there. I have seen multiple mentions of screen flickering on the forums but I am unsure if what I am describing is the same issue or not.