There have been graphical issues so severe for the past month that the game is unplayable in Linux.
This has been reported repeatedly in the Linux Bug report thread, with no reply in that thread from the devs.
It has been sent to support and the bug reporting form.
It is as if the Linux release is going out untested.
I have only run into ONE Linux user who doesn't have this issue. That user had a nVidia GPU that used the nVidia Legacy driver.
All Linux users who use nVidia current driver, Mesa Intel, Mesa AMDGPU, Mesa RadeonSI, Mesa R600, Mesa Nouveau, or AMD-GPU Pro driver have had this issue.
There is a second issue with the water in the background as well. It appears the shader is using the opaque "gray grid" placeholder texture instead of it's standard transparency, but it is hard to be sure without more debug information.
The water bug makes play difficult as you cannot see through the water from the top.
The pixelated lines, though make it unplayable, which is why I am posting this in a second topic.
There is a third issue with some transparency effects turning to black, neon magenta or rainbow color. However due to the low upload cap and difficulty reaching the a location that reliably replicates it, I will only post an image for these two bugs for now.
I didn't find the right solution from the Internet.