Well, I liked it.
I'll give it a 6/10. Decent thriller, worth a watch.
I actually thought they could have done more the killer manipulating them and turning them against each other angle. I thought he could have toyed with them a little more. Poor Brie was killed not long after finding out she'd been cheated on. They spent a lot of time setting that up, and then the guy who was behind it all shows up in person and kills them all pretty quickly.