May contain some general spoilers, but I'll keep it as broad as possible
Interesting concept but I felt the execution left a lot to be desired. Personally, I felt there were a few too many plot holes, along with crazy "rules" and plot devices they had to throw in to make the story work, and it was just too much to overlook. It is a movie based on time travel, so I guess that's to be expected though.
The acting was fine other than the mini-Rainmaker. I feel bad about calling out a little kid for his acting abilities, but it was the writing of his character that contributed to it just as much as his acting chops. Can you get a more cliche character? C'mon. JGL was good though, as were the others; seeing a bit more of Paul Dano and Jeff Daniels would have been nice though.
Overall, it was pretty entertaining though. Good action and some pretty memorable scenes, even if a lot were put in purely for effect and ignored logic (such as the Paul Dano torture scene).
7/10