Hi there! You should be able to exit most menus with ESC or X (as well as B/Circle on a controller). Can you tell us how you got this to happen?
I don't know actually! I just ran the game for the first time and I couldn't even exit the settings. It happened before with the steam version too
Could you try deleting the "engine.cfg" and "bindings.json" files from inside the %APPDATA%\Paper Lily folder?