Here's a comment by cantares on steam:
It runs nicely with WINE... You MUST however move the VideoDX11-*.dll to somewhere else or delete it.. WINE crashes when trying to initialize with DX11, DX9 works fine though.
According to his profile he has been playing the Steam version but I doubt there's a difference with Humble's or GOG's.
Unfortunately I could only find one person who claimed to have played it directly instead of a secondary source. My suggestion is to purchase the Humble version as that's DRM-free but with the advantage of possible Linux support in the future, at least a faster future than GOG's possible support.