A: Probably never because Balatro work fine with Proton. But, if you still want
to run Linux natively. Here's a guide made by a Steam user : Guide.
Q:How to access source code of Balatro and modify it?
A: Just right-click the “.exe” file and open it as an archive file. Now, just open the “.lua” files, modify them, and save them. Here’s a video if you still don’t get it.
Q:How to mod Balatro?
A: Install any of these Modloaders: Steamodded (Recommended), Bala-Mods or Lovely (Please no). And now just download Mods for that Modloader. And Put it in the Mods folder-Balamod-Steamodded. Proper Guide if you are still confused.
As someone who doesn't know much about what this game is about, except that it is some sort of luck-based card game: what makes balatro so popular? What makes it different from other luck-based card games?