A trick I figured out with Lutris for programs that don't have a one click setup from lutris.net is that you can just add the program's setup.exe or whatever manually, use an existing prefix for a game that you know works already, install it under the prefix like any other program, change the shortcut to run the game, and it works just fine. You can use any old program you grabbed off archive.org or wherever you source your games that isn't Steam.