Please step into my twisted little mind as I imagine how the "Darkness Falls" pitch meeting might have played out...

Fade in...

We see the story writer (Joseph Harris), the screenplay scribe (Joe Fasano), the Director (Jonathan Liebesman), and a Dimension Films Uber-Superior, a.k.a. "DFUS," sitting in a large boardroom across the table from each other.

JH: Ok, I think I've got the makings of a great new suspense film.
DFUS: Let's hear it!
JH: Here's the premise. About 150 years ago, there's this really nice lady (we'll call her Ms. Dixon) who lives in a lighthouse and has a few foster children. As their baby teeth start to fall out, she gives them a gold coin in exchange for their teeth. After a while, she is known as the Tooth Fairy, and her story spreads. Well, one day, the lighthouse catches fire, and Ms. Dixon is horribly burned. So bad, in fact, that she has to wear a porcelain mask to cover up her disfigured face, and she can only come out at night because the sunlight inflicts pain on her burned skin. When two young boys are missing, Ms. Dixon is blamed, and she sentenced to hanging. However, before she is hanged, she curses the town that has forsaken her, and vows to extract her revenge.
DFUS: Sounds good so far!
JH: With that, we now have an evil Tooth Fairy that can only move around in the darkness. She can't go into any light, or else she dies. The scary catch is, if a child peeks at the Tooth Fairy, she murders them! Think about the nightmares that will cause!
JL: Ooh yeah, I can picture that. This is an interesting twist.
JF: I'm liking the sound of this. After that background, I can start the story modern day, with a pre-teen boy who is losing his last baby tooth and placing it under the pillow. Later that night, when he wakes up from a scary dream, the Tooth Fairy is in his room, and he accidentally peeks at her, but he gets away! She doesn't get to kill him because he goes into the light, and she can't move out of the darkness!
JL: Nice. Then what?
JF: Well, then we'll jump to present day, when the boy is an adult, 12 years later, and he's been running from her ever since. He's still afraid of the dark, and now he comes back home to help another little boy who has seen her and is trying to survive.
JH: Uh, that's not really what I had in mind...
DFUS: So what happens for the rest of the story?
JF: Everyone around them gets killed by the Tooth Fairy!
DFUS: Oooh, a slasher film instead!
JL: I don't know if I can film this without the Tooth Fairy coming out of the darkness to get some of her victims.
JF: That's alright. No one will notice the logic holes because we'll get Stan Winston to come up with a cool creature!
DFUS: Cha-ching! Sounds like a winner! Here's a bunch of money to get you started!

...and fade out.

I wonder if my little fantasy is anything close to what really happened, because it would sure explain a lot.

"Darkness Falls" really does have an interesting premise, and the opening ten minutes of the film set up what could have been a suspenseful, scary thrill ride. But after that, and we cut to "12 years later," the film loses all sense of inventiveness. It's almost as if the film goes from the childish unknown of a something that comes into your room at night and you never see, to a grown up seeing the fantasy shattered for what it really is. Gone is the sense of foreboding and fear of dark corners and shadows, replaced by a scary prop that zips through windows like a battering ram draped in black cloth. Yes, it’s designed by Stan Winston’s creature shop, and the CGI-flowing cape is black and ominous, but the white porcelain mask has been done before (see “Scream” or “Phantom of the Opera”), and is it really that scary?

About an hour into the film (which only runs about 75 minutes), as Emma Caufield's character Caitlin Green runs from the creature, she proclaims "oh, this just gets better and better." Unfortunately, Emma, "Darkness Falls" just gets worse and worse until it finally dies a flat, horrible death and the credits mercifully roll.