https://bugs.winehq.org/show_bug.cgi?id=46558
--- Comment #8 from BabbleBones@gmail.com --- Issue has been found!
The game decodes a 16 bit grayscale png and uses that for height information on the planets. Somehow the png may be getting truncated on read.
What it truncates into I am not sure but it may be an 8 bit value that would wrap around and swing the terrain generation in crazy directions.
Saving the images back to disk as 8 bit grayscale png seems to solve the issue. Please see: https://github.com/ValveSoftware/Proton/issues/1792
How is png conversion from 16bpc gray to 8bpc gray handled? Is it an external lib or internal implementation?