My little boy enjoyed it, and he did say that it was a bit scary for him (he's six), so I take that into consideration if you were taking a child to go see the movie. Again I'm amazed at how the studio markets the film to kids, but yet puts it out as a PG-13 movie. Of course this is all about parents discretion, so ultimately it's your decision if your child should see the movie or not. All in all Kris enjoyed the film, and he had a fun day out with his dad. Dad didn't mind the film either. There is not much on plot except that Bruce Banner Hulk's alter-ego is always searching for a cure. It's what the TV series did so effectively week after week.
A few things to note here though. Marvel is gearing up their franchise. In the movie another super villain is created. If my memory serves me well it was the origin of the mad scientist who is green like the Hulk, and whose head is bigger because he is super intelligent. I don't remember what they called him in the comic, but look for him in future episodes. Also Tony Stark appears at the end of Hulk, and he says he's putting a team together. That and if you saw the end of Iron man and you saw the conversation between Stark & Nick Fury about the "Avenger initiative" you know whats coming. Only time will tell to see how Marvel studios puts it all together. I'm sure my boys will be their target demographics.
Needless to say I liked the "Incredible Hulk", and it was an enjoyable picture to share with my young son. I'm sure Marvel is betting on other dads to take them and share a superhero both know about. That's the magic of it. For us older folk we're flooded with memories of nostalgia, and for the younger crowd they are thrilled to find out about another "new" superhero.