I loved this movie. Yes, it's complex and slightly confusing at the beginning...but that also means it's deeply layered and worth watching many times. It's a perfectly-done production, excellent acting and fantastic effects. But the concept and story are even better.
It's not all action (although there's plenty!). It takes its time and reveals layers of story throughout the 2.5 hours of the film.
If you liked The Matrix, Dreamscape, or Dark City, you will LOVE this movie!