You could probably make a strong argument that Run Lola Run is a sci-fi film -- a breathless examination of divergent timelines and cause and effect. The Princess and the Warrior's heady, existential ending also places it just left of being a straight drama. German writer/director Tom Tykwer has tackled romance, period horror (Perfume: The Story of a Murderer) and the suspense thriller (The International), but he has yet to add an honest-to-goodness science-fiction film to his resume.
Why not? Tykwer seems like a good fit for a cerebral sci-fi tale, something along the lines of Solaris or even The Fountain. As a director, he's not afraid to ruminate on big thematic ideas. He examines the concept of destiny in two of my favorite Tykwer films, Run Lola Run and The Princess and the Warrior, and completely separates them stylistically. Run Lola Run is relentlessly energetic, fueled by inventive editing, adding animation and freeze frame asides as artistic flourishes to an entertaining story. Lola's story is one of divergent timelines and how the seemingly insignificant things that you do can have a profound domino effect on your fate. The Princess and the Warrior is a film dominated by two great lead performances (Benno Furmann and Lola's Franka Potente). It's an emotionally raw and challenging story, wrapping up with an ending that couldn't possibly be seen as literal--a cinematic mindbender used to punctuate Tywker's point about how we are the captains of our own destiny.