https://screenrant.com/back-future-eric-stoltz-marty-mcfly-change-movie/
Back to the Future originally cast Eric Stoltz as Marty McFly, but he was replaced during production. But what would have happened had he stayed?
From what I've read he would have gotten his block knocked off by Tom Wilson.
https://www.cinemablend.com/new/How-Shooting-Back-Future-Cafeteria-Scene-Left-Bruises-Lot-Resentment-72247.html
I think Back to the Future would have maintained the same level of fun and enjoyment, as well as popularity, that it otherwise had, if the rest of the cast was the same anyway.
Eric was fantastic in Caprica, one of the many reasons to watch that series.
negative. while a great story. the film is carried by Fox's amazing youthful energy that perfectly matches.
I believe Eric tried to play it too straight and serious.
Eric Stoltz in Back to the Future
https://www.denofgeek.com/movies/back-to-the-future-never-see-more-eric-stoltz-marty-mcfly-footage/
As the Broadway musical gears up, it's time to reflect on one of the greatest casting decisions in movie history: Replacing Eric Stoltz with Michael J. Fox in Back To The Future. There's been so much written and said, but it seem obvious that BTTF is a really beloved classic with Fox and almost certainly wouldn't have been with Stoltz. There are a few scene with Stoltz that have been put out, none with him doing any dialogue. Tom Wilson who was pretty unforgettable as Biff said that they had almost finished the movie when Stoltz was fired. Co-creator Bob Gale said the reason you'll never see an entire performance is because Stoltz just isn't very good and he doesn't want to further embarrass him as he is still a working actor and director. I also have to believe that his contract would specify him getting paid again for any releases with him speaking dialogue. And Wilson said simply that Stoltz was bad and very unfriendly.