With Proton Experimental, I haven't had to switch resolutions like other reviewers have mentioned for the player to render. Everything that I've tried so far (I have not tested multiplayer) works perfectly without any tinkering aside from the mouse not appearing on the main menu when in fullscreen (I'm not sure if that's how it's supposed to be, as I haven't tested the game on a native platform). I just use arrow keys to navigate the main menu and it's fine :P