I recently found about about Proton aka Steam Play, which is basically Valve's custom fork of WINE with built-in support from the Steam UI, so I thought I'd give SiS a try on my Ubuntu-MATE 18.04 system. Aside from red giants not displaying correctly, it seems to work pretty well!
The only issue I encountered was that red giants seem to render strangely. Everything else seems to work fine, though I haven't seen all of the weapon effects in combat yet. Coilgun/laser/missiles effects seem to display fine, so I don't see why any of the others would have issues, but you never know.