I'm making a simple puzzle game.
I can very easily detect if a player touches my GameObjects, by turning on colliders and using OnMouseDown.
In my game, when a player touches a GameObject... that GameObject starts a particular action.
The most intuitive way for a player to stop that action is to just touch anywhere on the screen other than that particular GameObject (like say, the empty screen). That way the game will know that the GameObject has no longer been selected.
How can I detect if someone has touched an empty screen?