Tidycade
Free game launcher for Windows and Ubuntu: install, then play.
...Guide/Home, or hold Back + Start where Home is reserved, opens the controller menu. Confirmed normal close supports switching owned native games. Unknown, detached and browser windows are not force-closed. Keyboard/mouse and the visual browser launcher remain available.
Ubuntu and Windows-under-Wine checks used virtual inputs and selected real games. No physical-controller, native-Windows hardware or every-game compatibility claim. See the release README.