A summation of my reviews for the first two entries in the 'Hell House LLC' trilogy would be that writer/director Stephen Cognetti wasn't getting the regular scenes in his movie right, but that his horror scenes were world class. Interestingly 'Hell House LLC III: Lake of Fire' serves to prove that the opposite of that is a much worse thing. This film has far better acting than the first two and also the dialogue is much better written, and yet it is the weakest of all three by a significant margin. Why? Because he forgot about the horror this time around.
The film has a tremendous amount of over-lapping shots from the first two films, mostly to show what happened in a certain part of the hotel/house or who a certain character was. At first this is helpful, but then it happens far too often from there on out and becomes very annoying and distracting. I think you just have to have faith that the audience has seen the first two films, and if they haven't then the information they are missing out on isn't hugely critical to the enjoyment of this one.
I think Cognetti was so intent on wrapping everything up into a nice little bundle storywise that he forgot what made the first two films so good, which was the epic horror sequences they featured. This one has little moments here and there, but there is never that big payoff that the first two films achieved. 'Hell House LLC III: Lake of Fire' was a little bit of a disappointing way to end an otherwise very good horror trilogy. It's not unwatchable, but it is a big step in the wrong direction.