You would think a Back to the Future game would be good, but no.
First off, that music. What? It doesn't sound like BTTF. Well, for the NES, that's forgivable. The music on this game still sucks. It's horrendous. That music alone is a reason to just put the game down, and put in something good, like Mario or Zelda. But then the gameplay...
It also blows. You go around collecting clocks. Remember that in the movie? See, you race against two clocks, one is the photo of Marty and his siblings that can be refreshed by collecting the clocks, and another that lasts 200 seconds and cannot be refreshed. When either timer goes to 0, you die, lose a life, and start from the beginning of the level. Also, touch anything, you'll have what looks like a seizure and delay you from moving and get rid of any affectable items and characters on the screen. The enemies make little sense. Now, there is a Biff like character, but there are things like two men with a pane of glass, a girl with a hula-hoop, killer bees, and birds. To help you in the mission of running down streets, you get two power-ups: a bowling ball to kill enemies, and a skateboard to speed you up. Now sometimes, these are in front of a wall, and you run into then, and then you seize. After the walking stages, there are bonus stages. First is set at Lou's, then the next at the school, then the dance, and finally, getting back to 1985. These are very, very, very, very tedious.
In short, don't play this game. Watch the movie, but not the game.