It is a great movie overall in terms of idea and in terms of technological brilliance. The time traveling is handled in a scientifically semi-accurate way which makes some sense at every description, so I was pleased with that.
Aside from that, allow me to list the cons:
- The actors felt like they lacked motivation throughout most of the scenes. There were a few who seemed real -- the older brother and the grandmother to name a couple -- but apart from them, the cast seemed to be filled with actors who lacked real emotion through the film. Either a directing flaw or an acting mistake, the emotion falls flat or just feels completely fake throughout the film.
- The characters make terrible decisions that make absolutely no sense. "How do I stop a person from being in this one location at this one time?" Wrong answer: "Meet them there at that one specific time and try to make them move! That will definitely work!" How about you meet them earlier in the day? Or even better, before they leave the house? That would solve pretty much everything in that scenario. "How do I stop a robbery from happening?" Wrong answer: "Call the cops slightly earlier and hope they arrive on time." Or worse: "Appear in the store a day after throwing a slushee on a customer and hope not to get attacked by the robber. Surefire plan!" How about you inform the bodega man how the robbery will take place so he could lock his back door? Or how about you do literally anything else in order to delay the robbery longer? Maybe talk to the man longer to stall the robbers? That would delay it long enough to allow the brother to move beyond that spot beyond that time. Then leave? Be done? Sure. Easy. Or any other number of actually logical choices.
- They are time traveling to a point, and then having 10 minutes to get to where they need to be. Pick a better spot than all the way across the city.
- They are time traveling to a time and acting as if they got there too late. Go back and go back further. You have a time machine. Use it.
- Terrible ending which leads to no conclusion at all as it is so ambiguous. A better ending could be found at almost any end of conversation throughout the movie, where the movie has some shambles of conclusion. Instead, they throw out all hopes of closure and end with perfect ambiguity for a horrible ending with a hard cliffhanging that kills the whole film and makes it not worth watching.
- The whole movie pushes the "Black Lives Matter" and police brutality thing to the audience. That's a good thing. But what's a bad thing is the way they do it. The cops are unrealistic, they seem comedic, and they act like they are harlequins. If you are going to portray police brutality, make the cops real. Make it all real. If you have a cop shoot someone, they are SHOOTING SOMEONE. They aren't going to be calm or comedically exaggerated beforehand. And they ONLY show the violent protest. Not the peaceful. Not the genuine ones. Only riots. That's not how things work all the time. That does harm not to show both. It puts a negative and bad spin on protest which only weakens the argument of the movie.
- The main characters are shown as tough and as violent regularly throughout the movie, so the whole "police brutality" argument is even further weakened through this film as the characters gather less outrage from the shot. If they didn't have CJ as a quick tempered and violent child, and if the brother didn't seem so quick to stand up and get in peoples' faces, then the pity and the outrage from the shot would increase and would overall be better.
In conclusion, while the movie is slightly realistic scientifically, it also greatly ruins its own points and weakens its own arguments at the same time that it fails to satisfy its content and its audience with the skill and writing that the movie deserves and should have had.