This is a great movie, I just finished watching it. In fact had it not been based on an established franchise and it would have been a hit. It was also released at a terrible time.
I am an astro fan and was looking forward to the movie until the first trailer came out, after that I just couldn't get excited, it felt NOTHING like what Astro is, it felt way too westernized.
Now that I've watched the movie I was surprised by how much I enjoyed it, they definitely westernized it but not in a bad way. The story was definitely entertaining.
Now to my gripes, some of them are nitpicks and some of them are only minuses because the movie is based on Astro Boy and if it wasn't they wouldn't be. Astro Boy felt out of character, he was portrayed as a robot who thought he was toby and acted as a kid, Astro is supposed to be "stupid" and not notice he's doing things wrong and definitely not act like a kid. The ending bothered me that everyone he just "revives" and that he is a hero and everyone loves him including Tenma who is supposed to just abandon him. First of all Astro is not a hero, he's never been a hero in Japan. To their defense they've always marketed Astro Boy as a hero in the US, even Sony did this with the 2002 show even going as far as to tell Japan to make astro in the new show more "hero" like. And he is not supposed to be loved at the end, people are supposed to still hate and mistreat robots.
I guess since the movie won't have a sequel it doesn't matter that it ended on a good note and its actually good it did that. But had the movie gotten a sequel it would have bothered me seeing that aspect which is a big one from the Astro mythos gone. Its a shame it borabed because I would have liked a sequel with Atlas and/or "greatest robot in the world". Too bad skunk didn't have a cameo too!