As a fan of time travel movies, this one was a disappointment. While the time loops make sense from a logic perspective, they're pretty basic, and don't really add anything to the genre. Nothing unexpected happened. There was a lot of casual violence against women that was distasteful at best and didn't contribute to the plot or characters.
But what really made this movie BAD for me was that in order to force the plot to work, the main character, Hector, had to alternate between being portrayed as a naive dolt and a calculating manipulator. He switched between the two frequently and for no good reason. There was no consistency to his character, and he came across as a plot device stuffed awkwardly into people clothes.
For example, sometimes Hector would act on childish impulse, like [SPOILERS] when performing small acts of rebellion against the scientist's "rules" (such as not using the telephone). He seemed unable to help himself or grasp his situation. Then, after another quick trip back in time, he acts with careful planning and ruthless precision as he sexually assaults a terrified woman with complete detachment. All this without any compelling reason. He stabs his past self in the arm, while still suffering from said stab-wound, in order to preserve a future in which his wife dies, all while trying to change that exact future. Or, he sexually assaults a woman so that the audience gets to see breasts, and then stabs himself in the arm because that's what happens the first time round and the writers just made the character go along with it, even though he had no personal reason to do so. In fact, he had good personal reason to mess with time as much as possible to save his wife, but he doesn't do that. Instead let's have a convoluted and unnecessary sequence to bring back topless girl, who has to act inexplicably compliant, so we can have an action scene on the roof.
The idea that someone would go to both criminal and self-harming lengths to preserve a future they're also desperately trying to prevent, is hard to swallow.
It's not like you've got Predestination-level complexity here. There is room for at least one realistic human character. And it's not like the idea of time loops, encountering your past self, and the idea of fate were new in 2007. Predestination, which had far greater complexity (and even had characters that resembled real human beings) was based on a short story (All You Zombies) that was written back in 1958.
Two stars because of the hand-binocular scene. That was pretty funny. Otherwise we'd be down to one.