Holy Cousin Matthew!! I never would have recognized Dan Stevens as David (sorry, "David") if I didn't know the actor by name.
I hesitate to say much of the plot. I actually didn't know much about it going in, which sometimes is the best way to see a movie. One thing I will say is that this is not strictly a horror movie, it's more of a thriller (in terms of broad genres). It's a fun little escapist movie where you might find yourself feeling a tad bit too sympathetic towards the bad guy (and he IS bad). In real life, of course, you'd call the police and have him carted off, but in the fun of movie-watching you might rather wish you could have him carted off to your bedroom.
When it was over, I said to myself "That was a great flick." And I mean that in the best way. If you saw "You're Next" and liked it, you'd probably like this one (both from director Adam Wingard). They're both a little throw-back-y and they're both really well done. Of especial note was the '80's synth-y score.
And it's not that this movie is without its charms. I think upon a re-watch I will like it better. Part of the problem was simply that I was so annoyed with the kid in the movie that it took me out of the spooky realm I needed to be in to be captivated and taken away by the horrors. I just wanted him to shut the fuck up already and let his mom get some damn sleep.
Cuz DAMN. That poor mom, Amelia. And I get that the kid is supposed to be annoying. And for once he wasn't annoying in the sense of "shit, that child actor is horrible." The actor did an admirable job. I just couldn't see past it somehow.
Oh, and I cannot BELIEVE I got through the whole movie and did not realize that Amelia was played by the actress Essie Davis, who plays Phryne Fisher on Miss Fisher's Murder Mysteries. Holy fuck. She's so glam as Phyrne and Amelia was the exact opposite (but still fucking gorgeous anyway).
All that said, I would definitely recommend this movie. Just not as heartily as I would recommend The Guest.