So turns out a lot of games just work with no fuss on Linux if you run them through Steam, either through acquiring the game through Steam or slapping it on there with the "add a non-Steam game" functionality
You do have to set them to use Proton but otherwise it's painless.
With the exception of RPGmaker games that require RTPs, but there're workarounds involving putting the RTP files in the game's folder.
And editing the game's .ini file to remove the bit after "RTP="
And that easy of process is largely because the Steam Deck runs on Linux so Steam spent a lot of effort on making sure games would run.