I discovered http://cardgames.io games work great on my #Librem5 as a Gnome Web local app with its own launcher icon. While I already had solitaire and other games, this adds games like cribbage that don't have a native Linux app.
@spacemanspiffy Gnome Web creates a special configuration sandbox just for this website (so no linkage to other settings or bookmarks or cookies) and creates a corresponding .desktop link that opens Gnome Web to that website inside that config sandbox. Still needs web access though.