This film has almost nothing in common with the real events of the Commandos that did the sabotage at Rjukan. It is just a cheap Hollywood movie that tries to get credibility by stating - based on a true story. Like so many other WW2 movies from Hollywood. This also skews the truth so much, it is not even close to what the heroes experienced back then. As a movie however, it might be watchable. If you want the real story, you might want to look for the BBC documentary about the subject. A well done documentary that tries to recreate the conditions and experience some of the hardship themselves. They don't come close to what the actual heroes did, but the effect of what they do do is pretty amazing in itself. And it just makes the actual event even more incredible!