I originally penciled in a 1 star rating, because of (1) bad acting and (2) the unexamined un-self-aware bourgeois-ness of the whole Friends dinner for 8 scenario.
Upon Googling, however, I realized that this was a movie of true improvisational acting, where the actors were given (for each day of filming) several items that they were to accomplish through improvised acting, without knowing what the others were meant to accomplish. So rather than bad acting, it was simply the classical over-emotionalization inherent in an improvised acting class (one that falls back on channeling Halloween-type horror movies).
The other positive outcome of Googling was finding out the very elaborate plotting of the many-worlds scenario. Very impressive, and normally (i.e., if it weren't for the bad acting and the bourgeois unselfawareness) it would call for a second viewing to see how creative this actually was.
But this movie was made 20 years after the bland privileged normativeness of the TV show Friends, and I'm afraid it's simply a dinosaur in 2014. As it turns out, I'm sure this is a result of pusillanimous improvised acting--too unaware or too timid to break away from its suburban lowest common denominator.