Apparently a relevant fix got into Proton Experimental already, bleeding-edge not even required. Just started the game, was pleasantly surprised to get into the menu, but didn't play, so consider this more of a heads up ...
A Proton developer has informed me that the game runs with an internal test version of Proton 9. So we can expect the game to work once that is released. Furthermore, one of the game developers has also expressed interes...
It takes quite a while to exit likely because it's making massive crash dumps. Actually I wanted to include that in the original post, just had too much going on already. Beware of /run filling up after multiple runs! To...
Tried it on my oled deck with Experimental, it just gets stuck on the spinning steam logo for like 10-30 seconds before silently exiting out to the game library page.