I have a hard time being critical right now because one of my life long fears is of small children singing creepy songs. Oddly specific and yet terrifying and inclined to show up in any nightmares I have. So anytime there was the singing in the background I tended to be slightly terrified and not much good for thinking.

That being said I do think this episode would've worked better in the first half of the season. And hopefully we'll get a scene where the Ponds deal with leaving Melody behind to become River. Perhaps the next time River shows up?