Captain America is definitely a comic book movie. With a host of "yeah-right" comments amply strewn throughout the movie, you have to watch it for what it is: a comic book movie. If you can do that, you'll enjoy it. It was well done, well acted, and well....fun.
The star is that guy from Fantastic Four, Chris Evans, you know, the one who was on fire half the time. He's buffed up quite a bit and seems to fit the Captain America role perfectly as he presents a powerful hero who's shy and inexperienced around women. Hugo Weaving is the villian and does a good job at it. I couldn't help but expect him to say, "So, Mr. Anderson." Tommy Lee Jones is great. He's a convincing military leader. I loved his line, "If you have something to say, now would be a good time not to say it," when he was talking to Captain America's love interest played by Hayley Atwell.
Okay, so the plot. A skinny kid from Brooklyn is desparate to join WWII and go kill Nazi's. However, his diminutive size and long list of medical "issues" means he's a 4F. But, as the movie plot goes, he's chosen to be the subject of an experiment to make better soldiers. Why him? Because he's got character. That character comes shining through as he is miraculously changed into 1940's stud material and ends up kicking a lot of enemy butt. Is it enjoyable? Yeah. It is.
What was great about it - there was no sex and little, if any, foul language. I'd let my kids see it.