I don't get all the negative reviews -- this movie actually has a lot going for it. And personally, I've always liked this kind of tripartite structure, whether the three separate stories interconnect at the end (as is the case with this film), or connect only through an actor or general theme (as with my favorite, 1955's excellent "Three Cases of Murder"). I was entertained by "Amusement:" it is not just a flick to help waste your time, and the folks involved in its making clearly wanted to make a good movie, despite the budget.
As mentioned, "Amusement" consists of three stories with somewhat open endings, all three of which are resolved in a common dénouement at the end. Other than the first story, which I felt was the weakest of the bunch, "Amusement" is mostly carried by the main actor, Katheryn Winnick. Despite her demure clothing throughout, Winnick is decidedly more Playboy-bunny (well, a very athletic bunny -- she is after all a Taekwondo champion) than ordinary-girl-next-door, and at first I thought she was slightly mis-cast. I was wrong -- not only does she give a truly solid performance (notably better than the norm in these sorts of roles), her inherent sexuality seemed to enhance the sense of a strong, tough woman who will survive no matter what. Winnick is much more than eye candy here; she actually carries the film.
The sets deserve a special mention -- they are above the norm. The pacing, and focus on telling a coherent story (really hard, I would think, in a movie structured like this) are also above-average.