Such an incredible film, and really quite difficult to categorize, since it works on so many levels.
On the one hand, it's a highly polished crime caper film on the level with (if not better than) Kubrick's The Killing. On another level, it's a well executed, epic action-adventure film (dozens and dozens of gun fights and sweet explosions). And on another level, it's a highly complex and deeply philosophical science fiction film. (The closest comparison I can find is either Total Recall, or Eternal Sunshine of the Spotless Mind, but this is a far better, and more polished film than either of those films.)