Yeah, I recently installed Wine (the Windows emulator for Linux) so I might look into Proton as well. I believe Proton creates a compatibility layer to run HTML5 Apps natively on the offline desktop if I understand correctly - no that's Electron I am thinking of. Right, Proton is developed by Valve/Steam for cross-OS compatibility of Windows Apps to Linux OS. I heard that Proton has been improved more and more over a period of time, with better compatibility results than previously. Thanks for the tip, I think I will check out Proton in addition to Wine. Actually, Proton is a fork of Wine or utilizes Wine if I understand.
As I understand it, Proton is how my first game, Mooselutions, can be played on the Steam Deck without any extra work on my part. If you ship a game on Steam for Windows, it's just automatically available on the Steam Deck via Proton. You have to make some adjustments to your Windows build so it plays well and looks good, but otherwise it's totally viable. Mooselutions got Steam Deck approved without any need to do a straight Linux port. Gaben delivers.