Wow, i was just IMDB to find some of the info above, and the movie has such a low rating. I did not expect that. Hehe!
Well of course it's not as good as the old Spy Kids, but it's not that bad. It has some really fun moments and i have already watched it twice with no difficulty. The kids are new actors and the girl wasn't one of my best to see around but the boy was really cute and funny. He really matched his role. Now, for Jessica Alba is definitely NOT one of her good movies. She felt in general a little out of place. Good thing of the movie is we have the old kiddohs which are now older, but don't expect to see many scenes of them.
As for the story it's not something wow and at the end it's confusing but the main message of the movie can be seen from the earlier scenes. And it's clearly a kids movie. Do not expect something serious. It's full of colors, and brother-sister, family stuff. I don't say that older people can't watch it of course.
One thing that is always really good at the Spy Kids movies are the gadgets ideas and the special effects. Both are truly amazing and i strongly believe that the 3D version is really good. I think every kid will enjoy the movie, and if you don't have the highest expectations as an old fan of Spy Kids, you will too.