Thanks for trying it out!
Your bugs are noted - most of them aren't bugs, but misfeatures. However, it crashing it obviously an issue.
I honestly didn't expect it to run on any Linux machines: so far, most don't see the launcher, but it plays OK otherwise. You have the opposite problem! Very weird!
It bothers me that you had to reduce to 800x600 and "fastest". I wonder if it's simply that your drivers don't do GPU instancing. That could easily cause both the Linux crash and the Windows slowdown. It's hard for me to tell. :|
I plan to add some debug features in to help users figure out what's going wrong, but I don't think that'll help with your Linux problem. If there's a crash log, I'd love to see it.