Saw this at the movies and didn't care for it. It wore me out trying to follow all the movie's "rules." Like "The Matrix" they try to tell you how everything works as you watch the movie. The only difference, is they do this so much, that it became tiring to try to follow. I wasn't prepared at the theater and "zoned" it all out.
At home, on the other hand, I sat and watched the DVD. Gave it all of my attention and discovered that there is no special meaning, no major twists that I had to catch, nothing that I had to watch out for. No tricks. Just watch it without trying to look so deeply into it and you'll enjoy it. I guess that i tried to over think it after hearing so much about people not getting it.
It could have been simplified some, but now, I'm a fan. It is a great movie and great to watch at home on DVD.
What's great about it: Great overall look. Great special effects.
What's not so great: Can be tiring, if you don't give it your complete attention.