I took the hatchling to see this at the dollar show (second run theatre) yesterday because he is a huge Jack Black fan. I have long enjoyed his work as well, but my 4 year old son didn't discover him until his guest appearance on Yo Gabba Gabba a year or two ago. He recognized him on the billboards for this movie while we were driving in the car, repeatedly asking me to see this. I was amazed that he would remember an actor who wasn't a cartoon character. Then again, Jack Black is as close to a cartoon character as an actor can get.
There are some SPOILERS from here on out, so don't say that I didn't warn you. This movie plays on the same old Jack Black formula, which I happen to love. Arrested development man-child with a crippling crush on a chick who, in real life, would never date someone like his character. Plenty of pop culture references for people in our age group, with plenty of Kiss and Star Wars being prominently displayed in this film. Lots of goofy dancing, fighting, and acrobatics. Jack Black may be a one-trick pony, but I really, really enjoy his one trick, see? This movie would have even been worth full price.
Fearless prediction: Jack Black will enjoy a career resurgence in 15-20 years. Once his career simmers down, there will be people my son's age who, in a wave of nostalgia, will begin clamoring for a return, and voila, Jack Black will have the John Travolta style career resurgence. Believe it.