Only video games up to and including the year 2000 can truly be called “retro” because they belong to a technologically, aesthetically, and culturally completed epoch, have sufficient temporal distance, and are unambiguously treated as a historical era by both the community and the industry. Everything from 2001 onward is “classic” or “old-school” within modern video game history—but not retro. Retro is not a question of age alone; it’s a question of a clear historical break. And that break lies around the year 2000.
Retro is anything made pre-2001. 9/11 changed pop-culture.