20 Things You Didn't Know About Unbreakable
2. The Film Is Entirely First Act
When writing the film, director M. Night Shyamalan realised that he was not as invested in the middle and ending portion of the script as he was the beginning. Originally, the story started as a very traditional comic book film, with the main character discovering his powers in the first act and then going on to fight the evil in the middle and final act.
The director found himself not responding to those later acts, so instead he stretched out the first act to last the entire film, so that the whole story was just the main character discovering his powers and how he deals with that. The film is an origin story and the birth of a comic book hero.
The sequels that the film would eventually spawn, Split and Glass, went on to fulfil those other acts, where the hero faces off against the ultimate evil.