The Steam installer still opens a Wine Command Prompt at step 3 of the installation process with *Proton 3.16-6 Beta*. The game will still install and play correctly though.
This game is working perfectly for me. I was also able to verify the touchpad mode is working. System Information GPU: Intel HD Graphics 3000 Driver/LLVM version: 3.0 Mesa 18.2.2 Distro version: Ubuntu 18.10 Link to full...