The first 30 pages of The Creepers reads like the start of a traditional horror thriller - a disparate group of people go into what they think is a non threatening situation which turns out to be exactly the opposite and nearly everyone dies a horrible death - but as the story progresses it veers into the format of a much slower moving, supernatural horror until right at the end, where it vacillates between the two as if the writer isn't sure whether they are writing a 'seven go in and none come out' shocker; or a slower, more supernatural/psychological horror.
If it's a shocker - the audience expects shocks and fearful murder throughout. Currently the first scare doesn't happen until p22 - p25, which is almost a third of the way though the script.
Why not set the tone straight away? Start with a big scare. Make it a good one. And keep the scares, and the deaths, coming. That's what most of the characters are there for!
As it stands there are eight potential victims but no-one actually dies until four pages from the end of the story. Put more scares and deaths in earlier, build the tension. Spread them out, make them memorable, shocking. Be creative. That's what drives the action in a horror forward. Shocks and death.
If it's a supernatural/psychological horror, structure the story differently so that it sets audience expectations correctly. There's no need for a team of victims. Just Devon, a couple of supporting characters, Mildred and some pissed off spirits. Decide - who's the main protagonist, what's going to happen to them, how's it going to happen, why's it going to happen and how are you going to make the audience care?
Here are a couple of things to have a look at when deciding which way to move with the story for the next draft.
Decide what kind of a haunting is at the crux of the story. This will helps decide what kind of scary stuff happens next. At the moment:
p12 - things going missing, moving about = poltergeist
Knocking on doors = poltergeist
Disembodied voices saying specific things = spirit haunting
p14 - faces in the walls, on the floor = spirit haunting
p22 - disembodied shadow, ghost or zombie = the undead
p58 - Mildred is now a zombie = the undead
Mildred - an old lady who called the team in because she was scared, but doesn't seem at all frightened when they arrive. Why would she still be living in the house? Is she nuts? Could she in league with the Creepers? Where did she get all that cash from? Would she really be using Facebook to contact Autumn if she's the kind of woman that doesn't like banks and lives in a shack in the back of beyond? How and when does she become a zombie?
p52 to p62 - We learn about the DeWolfe family and their history, who the Creepers are and what they want. This section is written with the most passion, attention to detail and conviction out of the whole script. If land theft from local people in Alaska is the story that you want to tell, use that as the starting point. Forget traditional horror, go for a supernatural/psychological thriller.
p58 - what happens to Greg after he sees Mildred? Is he dead? How does he die? Why don't we see it?
p66 - This scene is really jarring. It's out of character for the stone cold self absorbed character you've created in Devon to call her mum now. And where has this critical dream come from? It's a different dream to the one she had on p37. Maybe you could introduce her mum or references to this part of her back-story earlier in the script, to prime the audience.
p68 - There may be a better way of getting across the shock that she's a DeWolfe. A phone conversation out of the blue about something as emotional and life changing as being adopted under macabre circumstances feels wrong.
p70 - the team are now zombies. How did they die? When did they die? Then, after they've killed Devon, which we don't see, if the bodies of Mildred and the team are found by the police , presumably no longer zombies after achieving their goal of dead Devon, they wouldn't still be there to kill Ronnie a few months later when Ronnie returns.
p73 - If the spirits were after revenge on Devon, who is dead, and the police took away all the zombie bodies, who or what killed Ronnie, and why?
Characters
Devon - the main protagonist - is the most developed character. She's an unlikable, cynical, heartless, self serving mercenary bitch, perfect for a horror movie! This is established from page 1 and reinforced, mainly through the use of dialogue, repeatedly throughout the story. But there's not a lot to like about her, and no chance for her character to develop.
Why is she such a bitch to everyone? Does she have any redeeming qualities? Why should we care about her or what happens to her at the end of the story?
Have a look at the rest of your characters.
Troy - ex-partner/victim
Ronnie - the sensible one that gets away/victim
Autumn - victim
Greg - victim
David - victim
Shelly - victim
Mildred - victim
Why are they there? What does each of them bring to the story? If they're just there to get dead that's fine, but make them get dead in a surprising and interesting ways.
If they're there for another reason, love interest, enemy, friend etc, then make that clear and give them a bit more depth.
Dialogue
There's a lot of dialogue, particularly exposition dialogue. This slows the pace right down, which is not ideal in a horror movie. Look at the use of exposition dialogue, especially in the last 20 or so pages. From p58 on it's mainly static dialogue as the characters work out who's haunting Mildred's place. Is there another way to deliver the necessary reveals with more impact? Show the historical scenes rather than describe them, show photo's/documents?
Generally speaking the conversational dialogue flows, David and Autumn works well, but it doesn't ring true when some of the characters are speaking, Mildred and Troy for example.
Once the story is nailed down and the characters more fully developed it's likely the dialogue will hang together better.