Elfie Hopkins was filmed in the UK in 2012. It largely follows a slow build-up that is almost boring and looks more like a mystery film that shows its cranky and relatively lackluster protagonist as she investigates her new neighbors. She suspects that they aren't who they say they are and tries to get behind their secrets. That formula has certainly been explored in prior films and therefore doesn't really blow the viewer's mind. In the last 15 minutes, the film has some more graphic moments that weren't all that foreseeable before but they are still far from excessive.
Still, in Great Britain, those gore effects would have been enough to get the film the BBFC 18 rating. That was too much for the distributor and so they talked to the ratings board about possibilities to lower the rating by cutting out some of the violent content. The BBFC suggested the removal of two scenes and the "15" rating was no longer a problem in theaters. Unfortunately, this version also found its way on the home video releases in the UK and it took about a year for an uncut version to be released elsewhere. In this case, the US helped out when Elfie Hopkins: Cannibal Hunter was released straight to video with an "R" rating.
Comparison between the cut BBFC 15 DVD (by Kaleidoscope) and the uncut US DVD (R-Rated) (by Screen Media Films).
2 cuts = 9.68 seconds
1:14:51: Mrs. Gammon stabs Elfie's father repeatedly and Mr. Gammon isn't lazy in that regard, either. Mr. Hopkins face shows his agony.
1:23:51: The graphic CGI headshot is a few frames longer in the uncut version.