The acting was not excellent, but it was decent. I think Mel Gibson and Joauquin Phoenix acted well. The girl, Bo, was acted extremely well by Abigail Breslin. However I didn't like Rory Culkin's performance as Bo's brother, Morgan. I don't know what it was, but he didn't appeal to me as well as Abigail did. Phoenix did extremely well as a more laid back and crazy sibling of Mel Gibson's character (He also did very well at having a very hard to spell name). Graham Hess started out with being a boring character. He virtually lacked personality. I thought he resembled a Kirsten Stewart, until a very emotional scene where he began to cry. This was well done.
The movie, plot-wise, started out well. Several strange scenes with little to no music of a farmland being eerily left with crop signs. There was lots of suspense throughout the film. It didn't have much character development, but it wasn't necessarily essential for the story. However, the biggest con to this movie, was that this dramatic build up and suspense led to almost nothing. I was extremely disappointed at this, and the many plot holes that this movie contained. However I won't go into detail.
I award this movie with a generous 6/10. It was enjoyable, but it had more potential.