Even in action movies, things should make sense. A supporting character with an obsessive tick can be cool if it's believable. Shia LeBoeuf pretending to be a greaser didn't really work for me. His hair was wrong, and it looked like he was trying too hard. On the other hand Harrison Ford didn't look like he was trying hard enough. His delivery, especially in the romantic scenes, felt like he was phoning it in.
Also, I don't know if I like the idea (and I'm about to blow the ending, so if you haven't seen it, stop reading now) of the intelligence and innovation of ancient Civilizations being attributed to space aliens. It seems this odd attribution only happens with non-European Civilizations, as if to imply in some way that the level of intelligence achieved could not have been reached without some kind of assistance.
The only reason I didn't give this movie a 5 out of 5 is that I would like to have seen more fighting from the female characters. It was great to see the fighting styles of Jackie Chan and Jet Li in the same movie. Has me wondering, did they choreograph their own fight scenes. There's violence, but not graphic depictions of nudity or inappropriate language, so its a fairly safe bit of fun for the kids as well.
The movie was entertaining up to a point, but Angela Bassett, who has to be approaching 50 by now, playing a young single inner-city Mom in 5 inch stiletto heels? Her best friend was Latina painted with a VERY broad brush. One of her kids was constantly giving attitude and didn't get disciplined for it once. The rest of the script was standard Tyler Perry, religion, family, tragedy, a broken-hearted woman treated badly by a man, and a very funny cameo by Madea. Entertaining, but not outstanding.