Everything has a price

The main similarity I see between Donnie Darko and the themes of existentialism is the power and importance of choice. Basically the movie takes us through a series of choices that determine Donnie's safety and sanity more or less. By the choices he makes, to listen to Frank, and to do what he says, Donnie is determining his future; he is applying meaning to his life. Both the movie and ext. basically defy the concept of fate. This is shown with ext.'s believing that there is no purpose or point to existence beyond what each individual assigns to their own life with the choices they make. Basically, nothing is predetermined except that we will die. This theme is pretty evident in Darko, with the whole premise of the movie being that Donnie can go back in time, to choose to let himself die, rather than those he loves. The choice to die, after he learns about his situation, is where the entire anxiety and schizo-ness of the movie come from. The choice is what makes the difference.