I was waiting for this movie to come out, as I love a true horror flick.
Why I was disappointed with this prequel:
1. The funny scenes. True horror movies do not inject humor into the scary scenes. Why? Laughing pulls you out of the horror emotion and ruins the shock, suspense and mood that true horror should give the viewer. Fright and laughter are opposite emotions - laughter reduces the horror experience.
2. Too much modern technology. It destroys the mood and suspense. Scenes were too busy, too much blaring music and too much reliance on computer generated effects. The computer effects were also noticably flawed, which pulls you out of the moment. Instead of living the scene I was thinking how fake the effect looked. Makeup, mood, and lighting still out-horrors modern technology. A simple silent scene of a possessed girl floating down a hallway is much scarier than being bombarded with loud music and busy computer effects of attacking heyenas. The viewer's personal connection to the scene is a consideration as to why the original worked so much better - we all have a hallway, but few of us live near heyenas.
3. Must be compared to the original. I don't expect any prequel or sequel to equal the original Exorcist. Still, the prequel must be compared to the original to be fair. 30 years is a long time to formulate a decent prequel. Sadly, they dropped what worked in the original movie in favor of the Hollywood-esque formulas that ruin so many potentially good movies today. Acting is cliche'd and predictable, modern technology overused. The original Exorcist was a serious adult film of true horror while the prequel seems de-tuned for a younger audience.
4. Storyline flaws - there were quite a few loose ends and an overall lack of substance, which once again remove you from the mood, this time to ponder why the scene is flawed. While they decided to forgo the successful formulas of the original, they did use a girl as the target for possession, just like in the original movie. While this worked great for the original, using the exact same likeness for the girl in the prequel seemed like a cheap copy - same makeup and likeness of the original character.
Overall I'd give this movie a C-
I do recommend the original Exorcist movie from 1973. Better yet, the Exorcist Rerelease which came out in 2000 which has scenes added which were originally removed from the 1973 version.