I know that this is potentially something for the RimWorld forums, but upon launching the game, my system lags a lot (Ran fine in Windows 10, so not just my computer being a potato) and my cursor flickers and periodically disappears.
The cursor/lag is across my entire system, not just the game. There is no "Unknown Display" in my display settings.
I am using Ubuntu 16.10 on an HP Envy x360 with Intel HD integrated graphics on an quad-core i7.
EDIT:
This issue seems to affect all Unity games (Not the DE, the game engine)
Also, the mouse flicker issue can be fixed using gsettings set org.gnome.settings-daemon.plugins.cursor active false
as suggested in other Unity-related posts.
The lag is still severe though. Note that this is not an issue with my graphics not being good enough, as the games ran fine when I was using Windows 10.