Delving into this area of extremely low budget time travel sci-fi gets with it the inevitable comparison to 2004 film "Primer" which was a masterwork of excruciatingly hard sci-fi.
Here, the mechanisms are largely unimportant, even though there is an entire scene devoted to basically expo-dumping how it works in the form of hypotheticals and quizzing of a small group of four philosophers and scientists.
Some guy named Aidan is driving in his car with his ex-girlfriend when suddenly someone jumps in front of the car while he's driving at night and it crashes, killing her and hospitalizing him. He meets a seemingly loony old man in the hospital who tells him to go to a motel and go to room 41 and crawl in a hole in the bathroom floor. Earlier in the film, someone who looked exactly like him told him not to go to that motel. So naturally he goes in.
From there he learns that going through the hole and emerging brings him about 12 hours into the past. From there, he tries to change what happened with his ex-girlfriend and the like.
Where the film falters, for me at least, is that it seems to not be able to decide upon what type of "time travel paradox" to go with. The presence of himself earlier in the film and the revelation about the cause of the crash would seem to imply a predestination paradox where he is in a situation where time is fixed, and any attempt he makes to change the past has already been done.
But then at the same time, other mutually incompatible paradoxes are toyed with as well, including a "multiple universes branching off" and some others. Toying with many different ideas for time travel would be something interesting to see if done well; the problem is it is not done well here. In some cases we don't even know what is happening and the determining factor as to whether Aidan is able to change something in the past amounts to "Whatever the script feels like".
As well, it drags in several places, and takes an awful long time to get to a really intriguing "Wow" moment, by which time the film was essentially over with barely 10 minutes left. Whether or not the extra focus or attention to detail would've helped or hindered the film I probably wouldn't be able to say, but for what it is, it was a neat enough film.