Continuity mistake: At the end of the movie, when Robert has been resurrected as a tricycle, the bell and ribbon keep moving back and forth from the right handle bar to the left one.
Other mistake: Blake jumped through the window, shattering the glass and propelling many fragments through the air and towards/onto Edgar and Zoe, but no-one got cut. (00:34:10)
Visible crew/equipment: When Mister and the Boy are keeping watch in the woods, just after Boy asks "What are we going to do when the baby comes?" They heart a noise and stand up, as the camera follows Mister you can see lights in the distance, even though they are supposed to be alone in the mountains. (01:20:00 - 01:21:00)
Audio problem: Throughout the entire movie, the audio cuts in and out many, many times. It even happens while characters are speaking. (00:04:42)