Works OOB with stock Proton 8.0. No tinkering needed.
The game runs great with 8BitDo Pro 2 controllers in X-input mode.
gamemoderun %command%
works out of the box installation with proton 6.3-6 / proton experimental
the keyboard config works great. however in regards to joypads i had different experiences. by default the game ran very well when using xbox 360 wireless controller. the wired xbox 360 ran fine too except three occasions it would pause the game which inst a big deal. the game detects the xbox game pad and changes the button configs to the xbox buttons appropriately .
i next tried the game with my 8bitdo M30 wireless controller. the game detected the joy pad however during gameplay, the connection would get cut off and i would have to reconnect constantly.
then i tried a basic cheap generic sega game pad knockoff and the game couldn't recognise all the buttons.
overall the game works best with an xbox 360 controller for me.