* In GOTG, Ronan was challenged to a dance off by Starlord.
* In Ant Man, the family had a pet giant ant at the end of that movie.
* Iron Man's costume is falling apart in Iron Man III and played for laughs.
* It's been a while, but didn't Iron Man III also end with Tony using his extra suits to make fireworks or something silly like that? Maybe that was Iron Man II...
I'm sure I can find other examples, but those are 4 just off the top of my head.
Kid friendly is a better way to describe Marvel movies. I take my kids and we all usually enjoy them but they are forgettable to me. I prefer comic films like Watchmen, Nolans trilogy, Dredd, Man of Steel, The Crow (original only), but you get the idea. I am really looking forward to Civil War though as Winter Soldier is one of the few Marvel movies I'll rewatch.