Tried a few different versions of Proton after the download (6 hours) completed and installed, 7.0-6 was the only one I have had any success with so far tonight, after the Piranha Games title and warning screens cycled I arrived at the "press any key to continue" screen before the main menu. While the cursor moves around and the background animations and audio play the game will not respond to keystrokes or mouse clicks. I was able to exit via Alt-Tab and then clicking the stop button in Steam.