A limbo state within a dream, within a dream, within a dream, (within a dream?).
It reminded me of recursion in programming, waiting for it all to unwind.
Not to mention all the rest of the things which just added to the complexity of the whole experience. Don't get me wrong, I enjoyed it and could follow the plot, but it constantly felt like it was adding complexity just for the sake of it, not necessarily improving the experience.
I don't really understand why they had an entire training montage where she learnt to bend the world, experimented with physics, limits of dreams, even taught her some clever tricks such as 'penrose stairs'. Yet, when it came to her utilisation in the film, she was not seen to do anything? (I know she designed the levels, but ultimately her role in doing that seemed to be ignored. I was awaiting her to use her 'amazing skill' to do something great to help save the day.
Many of these ideas were presented in The Matrix but the "idea" of n-deep illusions was central to Inception. I appreciated the time multiplication, even given the 20x fast brain function bodge.
Why were the acceleration changes only go one layer deep? Perhaps inner ear sensation (balance, acceleration) in the dreamer's world are the only modifiers. It doesn't matter, the construct produced intriguing new effects that I was pleased to experience.
We should be arguing about interesting ramifications. Personally I'd like to believe that Mal was correct and Cobb was dreaming all through the film.
The film reminds me of a couple of Red Dwarf books: http://en.wikipedia.org/wiki/Better_Than_Life (especially) http://en.wikipedia.org/wiki/Last_Human These are definitely worth a read if you are interested in science fiction.