*Spoilers Ahead*
Here are a few things wrong with this movie:
1. This movie does not have an ending. It's like the director ran out of budget before one could be created. That instantly knocks three stars off the review for me.
2. The protagonists create a time machine and plan to use it to get a scholarship. They are completely ignorant of the magnitude of their creation and the harm it could do if it fell into the wrong hands. The protagonists were very smart, but also extremely dumb.
3. If they wanted to save Claudette's brother from being murdered, all they had to do was go back to the morning of the shooting and cut a powerline to the house, break a window... some minor inconvenience which was enough to change his day with a minimal chance of negative consequences. There were many ways they could have kept him off the street.
4. They should have involved their genius classmate sooner to help with planning.
5. They could have jumped to a closer location to where Claudette's brother died to save time.
6. Claudette's clothing was not appropriate for the setting. NO ONE IN THE HOOD DRESSES LIKE THAT.