It was ok. I think it is appropriate for your children- I have children age 3,5, & 8 as well. I does jump around alot which got a little confusing.
Of the 3 kids movies out right now I much preferred Monsters in the Attic (a little more geared toward adults though). My kids favorite was G-Force.
We usually don't go to this many movies, but we were trying to get in a few fun things these last couple of weeks before school since we didn't go on vacation this summer.