The phrase "full playthrough" means completing a video game or any form of interactive media from start to finish, without skipping any parts or levels. Full definition
To see more, including full playthroughs of more levels, visit its official website. (killscreen.com)
After giving Dark Souls so much flak, why did this «Souls» game set my loins on fire and compelled me to do two full playthroughs in the space of a week? (egmr.net)
Even in one pass, which will likely * not * be the only full playthrough one does, I have a very hard time believing this 10 hour rumor. (blog.us.playstation.com)