I had the issue with the launcher and config all working fine but when I started the game itself, it'd seem to start fine but not show on the screen. This is with 'Ubuntu Gnome' and the default Gnome desktop. Turns out the launcher was keeping the focus and the game was being stared hidden. I could alt-switch to it.
Disabling "Allow the window manager to control the windows" fixed this. Took a bit to figure out and thought I'd share to try to shortcut someone else's fiddle time.
We're rebels. We're misfits. But mostly, we're software liberators. And we're very, very good at what we do. We have to be. Lots of developers work with open source, but only a tiny fraction of those are good enough to get software that was designed for one platform to work on another one. We invented CrossOver software - a unique approach to cross-platform compatibility that does not require dual-boot or another OS license. We launched PortJump to help app and game developers broaden their market beyond Windows® users. And we launched ExecMode to help organizations solve really ugly technical challenges.