Great modern day slaspstick
Rocketman does what movies like Paul Blart or Zookeeper strive to do so hard and that's be funny and really goofy at the same time. I think the main ingredient they add is a likable main character. Fred is an idiot, but you support him because he really does love space travel. A lot of films today rely on your generic everyman with no interesting qualities other than that he's a nice guy.
Rocketman made me laugh back then, and it still makes me laugh today.
"That's the karma again, I didn't help Kenny so she beat me up with a telephone"