The "Days of Future Past" of video games in that it combines a dystopian future, time travel, the 1970s, and debatably even some mutants. A perfect sequel in that it takes everything from the first game and does it bigger and better. Levels have more interactive elements. Vehicles have alternate drivetrains. And the story is so insane it's hard to keep straight. If there was ever a movie to make out of a video game, this is the one.