Instructions to make it work on Steam Deck

[Default Player]

Use Proton version 6.x.x. None of the later versions, including experimental worked for me. Would mark this game as non-verified until it automatically starts with that proton verion or a patch finishes compatibility with the latest proton verion. Problem is the game not picking up the Steam Deck controller.
Using 6.x.x it was a smooth ride though.