I think the reviews saying this film was the best sci fi of the year or the best time travel film are WILDLY over exagggerating.
Whilst this is good its not even the best Joseph Gordon-Levitt film of the year (Dark Knight Rises was much better)
It is really nothing like the Matrix and a LOT like The Terminator.
Anyone expecting an action film will be disappointed, this is a lot more talky than we've been lead to expect.
Theres a paradox at the end:
At least that leaves the way open for a sequel if the whole cycle starts again a few years later! (VERY The Terminator!!)