Might be best to keep that final reveal...
...out of the plot synopsis. The reveal being that the simulation may have not been a simulation at all.
Not to imply it's the end of the movie (hopefully it's just a plot point), but that would have been more interesting as a surprise.
Right now it sounds like the plot of a Twilight Zone episode. Although, what follows the reveal could be the saving grace of the film. They could try something really unorthodox and garner some attention with a really memorable ending.
Provided they don't put it in the trailer or the plot synopsis.