Half-Life 2. Half-Life 2: Deathmatch. Have you played every single game in your Steam library?
No? Neither have I and that accomplishment is apparently just a small sand grain in the over 288 million games in Steam collections that have never felt a press of the Play button. That's a surprising figure from a new report by Ars Technica researching the most active and popular games on Steam straight from the recorded statistics of some of the platform's 75-million-strong community. Win-Win Conflict Resolution & Game Theory. Econometrics.