

Can confirm the path error
The game does not launch, only a popup window indicating a path error.
After i launched the game from the desktop mode it launched without problems. To make sure it worked i made it fullscreen 1280X800. Now it just works in the normal non desktop mode. Have not played for long but played a couple of songs and restarted the device and it still just worked perfectly, rumble, controller, music and all
capped gpu and cpu to lowest settings. But increased fps to 60 or else the game would constantly give a low fps warning.
it seems some startscript is not running correctly under first launche if not run from the desktop mode.
i had windowed mode as default and changed it to full in initial launch from desktop, so i dont know if it is needed to work in game mode.
to the question "Launching straight from Steam, would a typical gamer enjoy playing this game on Linux even without tinkering?" i answered yes because it seems to be a steam deck specific issue and not a generel linux issue. And even then the tinkering that needs to be made is so simple.
I tested Proton, native without SLR, and native with SLR (plus soldier and sniper). Proton won't launch, native won't launch, and while the steam linux runtime version launches, it plays about two notes of the music and then stops. The menu sounds play fine, but not the music. For a music game, this is unacceptable. Controller input also doesn't function in this configuration, and attempting to toggle to fullscreen locked up the game to where I had to restart my deck to get it to shut down.