An interesting concept with some very cool ideas that never really reaches its potential. Instead of exploring the implications of time traveling, the film sidetracks into a very rushed and hasty romance, one that never really makes sense. The scenes in the mental hospital add nothing new to the stock stereotype, and the ending is telegraphed a mile away. There are a few interesting ideas on time travel that are bandied about, but they ultimately go nowhere, and the military scenes at the beginning seem to serve no purpose for the rest of the movie. The story is flawed, but it's still interesting, the performances are great, and the visuals are kinda cool but nothing outstanding. An interesting concept turned into a decent film.<br /><br />The thing that bothered me most was the entire point of Knightley's character Jackie. At first I just thought she'd be a sign to Jack that he's time traveling, but then she ends up helping him and being the love interest? How'd that happen? There's a rather large leap from her throwing him out of her place to her going out of her way to help him. It felt like there was a scene missing. In fact, all the scenes in the future seemed to ignore continuity and logic altogether. It was a bit disjointed, even for a sci-fi movie.<br /><br />The ideas brought up by this movie on time travel have been discussed much better in other films and works of literature, so the film doesn't add much more to it. The movie's a decent watch, never causing you to lose interest, and the pace is perfect for this kind of film. It just doesn't seem to add up to anything special. It actually could have used a bunch more depth to it, to fill out the characters and inject some emotion and realism into the film. Still, it's an interesting movie, at the very least.