Had to use PROTON_USE_WINED3D=1 %command% in launch options or else the game would just crash and won't launch. Perfomance is okay-ish and game is playable. Some of the problems include: glitchy textures while playing, text disappearing and general weirdness if you try to change resolution, can't exit game normally by pressing exit button, instead you have to do Alt+F4 or to kill process with kill command in terminal.