Thanks for testing it out, and you are definitely right! there's should be a lot more information to reveal to a user, if not it's really "flying blind".
By right, the app should auto-restore from the point you quit (using a SaveOnQuit autosave) so you shouldn't need to manually load your previous work. But I definitely want to make the feature where you can just drop your .sml file into the app window and it will load it. :)