I never read any mention of "A Simple Favor", I remember when I saw commercials I thought that might be good. I watched on EPIX and it's worth seeing even if just for the two leading ladies, Anna Kendrick and Blake Lively.
I gave it a 7 out of 10, it's reminded of Knives Out, in the fact that I was ready for it to end way before it ended. It seemed to keep going on and on with too many twists. I gave it a 7 because the overall premise is good, the acting is good, the sets and outfits are good, and if it have been shortened about 20 minutes it would of worked better. Just like Knives Out, there is about 7 twists in the last hour. The first hour is the setup and it really good, sort of like American Beauty setup. Then comes all the twists and turns, maybe if they had eliminated about 3 of them and 20 minutes screen time it would of been a 8 or 9.