Well done dev, really good game so far!
I hope this helps some Linux Users:
The latest verion (2) has issues with the lighting being too dark on certain graphics cards if run directly through Wine. However, the lighting issues are not a problem if using Proton instead. I have Roshutsu added as a "Non-Steam Game" in my Steam Library and it works perfectly using various Proton versions.
Just go to Games > Add a Non-Steam game to My Library to add it.
You may need to go to Settings > Steam Play > "Enable Steam Play for all other titles" to enable Proton on Non-Steam games, I haven't tested that.
Thanks,
I hope @Jaguar doesn't mind me supplying this information :-) Will post on Patreon too