I really enjoyed the acting all-around, especially from the kids. It’s clear that they just let them be kids without too much scripting, making it feel very real, which of course made things even more tense when the kids were in danger. A lot of people didn’t think it was that scary, but personally I was pretty tense through most of the movie. They nailed the “off” feeling with the babysitter’s weird tangents and bizarre behavior.
It wasn’t particularly groundbreaking, and I don’t know if it’s worth watching more than once. But I enjoyed it from start to finish, and isn’t that what movies are really about?