Back to the Future II & III continues the adventures of Marty McFly as he travels to three different time periods (1985, 1955, and 2015) to correct various changes enacted by rival Biff Tannen and his progeny. Unlike the original Back to the Future game on NES, the follow-up takes place entirely from a side-scrolling perspective and features run-and-jump action inspired by Nintendo's Super Mario Bros. A key difference is that Marty can travel back and forth between the time periods to solve puzzles. The action involves carefully avoiding an assortment of offbeat enemies, such as spiked turtles and horned fish, while collecting keys, stars, junk food, nuclear fuel, and other items needed to advance. To win the game, you'll need to unlock 30 puzzle rooms and then retrieve an item that corresponds to each room's scrambled word.