It's just spooky enough to make your spine tingle, but I think it would appeal to people who don't normally like scary movies because most of the ghosts are just echoes of happy children, and the other one appears as corporeal as he did in life. Much like why I enjoyed El Orfanato, its predominant element is EMOTIONS AND FEELINGS as scenes trade back and forth between flashbacks to the story in the 1940s, when it was an orphanage, and the present day storyline.
A dusting of things I enjoyed:
* Suranne Jones! Maisie Williams! And the ADORABLE little girl who is so enthusiastic about everything, including their new roommates ("We've got GHOSTS!" she announces in the same tone one might explain they've just been given a new puppy). ETA: Oh man, she is the one named Pixie (we were remarking on that name in the credits)!! That is perfect. Pixie Davies.
Could not take Lucifer (Tom Ellis) seriously as a devoted husband/father, though, which is a shame, because someone better (I MAKE NO COMMENTS AS TO WHO) could have really shone in this role.
* The family has a Border Collie and even though he is absent for much of the film, CLYDE IS THE BEST.
* I was suspicious of "I'm not dead, Mummy," from the start, because combined with "it's cold and dark and I can see them, they're dead," that sounds exactly like something a new ghost who doesn't understand they're dead would say, but I still held out hope for her sake all the way through, and it was DEVASTATING to find out otherwise. Mad respect for managing to play me like that. Popular entertainment never lets kids you've bonded with actually turn out dead. (But I'm still unclear why, exactly, moving to the house allowed her to suddenly be able to hear him.)
* The house is beautiful, and I loved how scenes would fade from past to present, allowing you to appreciate the change in decor and style while still easily recognizing them as the same place
* I said it wasn't really a scary movie, but it did still have the amazing ability to give you a chill with something as simple as a cane whipping down out of nowhere, or a cellar door ominously lurking
* The young teacher in the 1940s is SO BRIGHT AND LOVELY. And the thing is -- I kind of want to both read and watch The Guernsey Literary and Potato Peel Society, but Lily James bugs me because she's too famous for the role. She's still stuck as Cinderella to me. But this woman, Olivia Cooke -- she's exactly what I want the main character in that movie to be. SO PRETTY.
* Also I loved her sweet little romance with the groundskeeper, though I am unclear why they had to sleep together, or how the whole town apparently knew. (also CRYING FOREVER that he never moved or married, waiting in vain that she might come back to him)
* Greatly enjoyed Young Percy taking exactly none of Maurice's shit, handily threatening him with physical violence and being the sweetest sweetheart in trying to get Stefan safe.
* The Semi-Evil Headmistress of the orphanage (Sarah Smart) was fun to watch, mostly because it was so bizarre how VERY much she looked like Kirsten Dusnt.
* We were all pretty sure we were going to find out that Miss Nancy Linnet died in the house, but it was zero percent less heartbreaking to find out exactly how and why. (P.S. NONE OF US NEEDED ZOMBIE-GHOST!NANCY rising out of the depths of the well at the end; that was so gross and awful and you were doing so well on not being a truly scary movie up to that point)
* The story of the orphans drowning in the house was chilling enough, waiting to find out how that occurred ("because their bedroom is on the top floor, right? so how could that possibly have happened?" we asked each other). The reality of how they died was SO HEARTBREAKING AND HURTFUL OMG. At least one of the ones who deserved it escaped.
* We did love the Children's Parade / Cold Case Ghost ending where they all leave the house, but I really loved that Evil / Insane Headmaster was like, "Nah, I'm good," and ominously went back to continue haunting his cellar, awaiting more children's souls and, presumably, torturing Maurice for all eternity until he finds them. Which, honestly, is what he deserves. I'm sorry you were brainwashed from the age of 2 or whatever but "murder is Bad, actually**" is not a hard concept.
(**unless the person you're sort-of-murdering is violently abusive and calls for help to stop it have been soundly ignored. You go, Stefan.)
Ugh, I'm not explaining this very well. Suffice to say it was incredible from start to finish.
BTW, I love my current state of soaking my brain in British television offerings. I don't think I've been back on this side of the pond since the summer of 2012, when I finished Lis Sladen's autobiography and wrapped up Law & Order: UK -- see there, I only just this second learned they actually did make 2 more seasons after that (14 eps total) before closing up shop.
After that, my shiny new relationship started to cut into my TV time, so between that and Glee being in superfandom state, wrangling American TV was all I could manage. But now I am BACK, and absolutely luxuriating in the riches that have collected in my absence.