Although, and YMMV on this, given the Cult Classic status this movie holds, it can be argued it was dragged down by the failure of Cutthroat Island. Nobody expected Renny Harlin to produce a successful movie after such a massive flop.
In the original ending of the film, Mitch died from his wounds after saving Charly and Caitlin. But it was decided that this would be too much of a Downer Ending and so Mitch survived and became a national hero.
Also, originally the name "Sam Caine" was simply a name her brain threw up as an anagram for "amnesiac". In the finished film it's her former alias.
The 100-year-old Windermere House in Muskoka was a planned filming location, but it burned to the ground before the scenes had been finished.
Studio executives considered rewriting the film to have a male lead, with Steven Seagal or Sylvester Stallone in mind.
The ice skating scene was scripted to have Samantha perform a double axel flip and shoot from under her upside down head. After testing it out on location and with green screen, they dropped it from the film.
A sequel has been in the talks for years, but to date nothing new has come up of it.