This is a masterclass in how to do a low-budget horrormovie.
There is not a lot going on in this movie. Some might even say that it's a bit slow. But since it's a short movie, it doesn't drag out and it manages to stay tight towards the end.
The style reminds me of Asians movies like Ju-on, The Eye and Dark Water.
There are some really clever shoots and some really effective shoots as well. Extremely well use of sounds and "off camera action".
The special effects are done smartly. We the viewer often see very little. This is exactly how to avoid using a lot of cheap and ugly CGI.
The acting is good. The mother superior comes of as being 100% authentic.It's almost like 'Dolores Umbridge' in the Harry Potter movies. On one hand you want to congratulate the actress for doing a good job, on the other hand you want to slap her in the face with a chair because you so thoroughly hated the character.
There are some flaws.
The shaky cam is done to death and annoying as hell. Most of the time it works in this movie, but "found footage" always create some plotholes. I mean, who found this footage? and who showed it? and why are WE seeing it?
It also has the same flaw as most haunted house movies: Why didn't they get out as soon as things started to go wrong?, why didn't they call for help? Why would you go around in the dark following creepy sounds?
BUT, if you are mature enough to suspend your beliefs for 75 minutes and jut follow the story as it goes, it's a pretty effective horror movie.
If you like scary movies, old buildings, creepy nuns and jump-scares this is the movie for you.