Edit: Oh, i should add: This is pausing for DEBUGGING. Not for development.
Under the edit menu, there are shortcuts to pause midgame (ctrl-shift-p by default), however i have found that it doesn't work when you are holding the mouse button down, and possibly when any other input is being held aswell.
So a workaround i use is to simply have a gameobject with 2 simple states that loop. In the start state use a "button down" action for whatever input you would like to pause the game that sends an event to the second state that with a "debug.log" action set to WARNING, and loop it back to the first state.