Back to the Future Commodore 64

Marty McFly, a senior at Hill Valley High, is late for class. But  after tonight, when he gets behind the wheel of a nuclear-powered  DeLorean invented by an eccentric scientist, Dr.Brown, Marty won't  be late for anything. In fact he'll be about thirty years early.  The year is 1955 and after hiding the car, and cautiously walking  through his hometown, Marty meets up with troublemaker Biff as well  as Lorraine and George, the two teenagers who will one day become  his parents. This is where Marty's real trouble begins as Lorraine  falls for him instead of George and Marty must now put things right  before he can travel back to the future. — Cassette cover

Back to the Future is the name of a 1985 video game released by  Electric Dreams Software for the ZX Spectrum, Commodore 64 and  Amstrad CPC. The game is loosely based on the 1985 film of the  same name.

Gameplay

The game is a side view arcade adventure. The aim of the game is to  get George McFly to spend as much time as possible with Lorraine Baines.  The more time George and Lorraine spend together, the more they will  fall in love, and thus more segments will be added to the family  photograph in the bottom right corner. The photographs in the bottom  right and left of the screen gradually disappear if the players does  nothing, thus setting a time limit on the game.

The player can find various object to help him such as love poems,  a cup of coffee, alien suit and a guitar. He also has a skateboard  to move around quickly.

Source:Wikipedia