You were right about the kid actors, some fantastic stuff in there. I didn't think it was a brilliant movie but I enjoyed it a lot. There were just too many clichéd moments, it was as if this was a film I love but I'd watched it 5 times already. The action sequence near the end was basically Cloverfield, which pushed it just too far. Nods to Spielberg, ok, but I was rolling my eyes at that point. Maybe it's best to watch this movie if you are not a sci-fi nerd.
Still, 8/10 for me.
The Tree of Life, anyone?