Runs full speed and without issue on Proton 5.0-10. Runs on Proton 4.11-13, but parts of the screen are cut off, forcing you to use the /windowed option. When running in 4.11-13, the screen will cutoff in the same locations as fullscreen, so it had to be dragged onto a different monitor. When using /windowed in 4.11-13, it also locks the ingame resolution options, disabling the ability to use a second display (which I couldn't get working regardless), and making it so you have to modify the game's config file to change resolutions. None of the newer versions past 5.0-10 that I tested would even launch the game.