While I won't give away any spoilers, what I will say is its a GREAT movie, and you should really go see it while it is in theaters! Its been described as a "dream heist movie", and has similarities to other movies like the Matrix (the first one), the 13th Floor, with touches of Memento. Here the cake is no lie ;)
The movie is nicely woven together with the special effects enhancing the story not overwhelming it like most of the summer block busters. The effects include traditional practical effects, digital effects, and cgi effects. The story also lets your own imagination fill in areas where needed and doesn't explain all the inner workings or backgrounds of devices and sequences. No worries of having something like midichlorians added here.
As a gamer this movie screams to either be a stand alone RPG or its concepts added into any current ones. Fantasy, Horror (which apparently the movie was first conceived as), and all the flavors of sci-fi (past, modern, future, etc.) There are so many areas you could explore, adapt, and use a game my head is still spinning. I can't go into too much detail without spoilers what you could add, or how you could explore a certain avenue. Needless to say i'm quite blown away by this movie, similar to when I first saw the first Matrix or the movie Primer.
I can't recommend this movie enough and I think I'm actually going to go see it again! Which will surprise some of you who know me as I don't normally make a second trip to the theater for just any ole movie. If you like some good juicy sci-fi flavor and go see Inception and you'll certainly be inspired by some of the concepts and may even incorporate some of them into your next game or RPG.