Okay, don't get me wrong, this is in no way the worst movie ever made. However, as much as Rob looks the part, his acting in the first half of the movie is very forced. Things that shouldn't have been funny were because of delivery.
Once they played baseball, the movie changed. The last half was really well done.
The only other thing was unless you have read the book (which most have) you miss important things.
I hope they make the second movie, and I hope they make it very similar to the last half of this movie otherwise it may fail.