"Playthrough" refers to the act of playing a video game from start to finish, experiencing the entire game or a particular level without pausing or stopping.
My approach with the first playthrough of games like Dragon Age, generally, is to play close to my own personality, so in terms of romance I was left to choose between Cassandra, the stern Seeker, or Josephine, the Orlesian diplomat. (hoogrambles.com)
In my first playthrough of Final Fantasy VI, I gave everyone Star Wars names. (gameological.com)