Speaking as an American, I used to not give a crap about the character Captain American. Nothing really struck me as interesting with him, but that was back when I also didn't know that much about him. After seeing the trailer for the movie I can say that from the start of the summer it was the only movie I was actually hyped up about seeing. I really don't think it will matter whether or not you're American on whether you enjoy the movie or not, or at least it shouldn't. Look at it this way, All of Marvel's recent superhero movies (save for Ironman 2 because i didn't like it) were all at the very least entertainable if not good so it's a safe bet that Captain America will also be at the very least entertainable and likely a good movie.