Children are lucky to have Robert Rodriguez. In between his ultra-violent action shockers, he makes fun little films for kids with the same enthusiasm and creativity, and while he panders to what kids like most, he never makes a stupid, soulless film. His Spy Kids films have been consistently entertaining in their high tech fantasy for children, and have been relatively successful as well.
The 4th film in the franchise stars an all-new cast, seeing as the earlier spy "kids" are full-grown adults now, but a very similar premise. A super-villain threatens earth (this time he wants to rob away time, so that everyone will be more with their families), a spy parent (Jessica Alba is the spy step-mom to Joel Mchale's kids) tries to stop him and ends up recruiting them via a hidden spy base in their home. Gadgets and fart jokes ensue.
Sadly, however, this iteration is tiring and shop-worn, and despite the 4D gimmickry, nothing else is fresh. This isn't a fresh take on the superhero franchise, this is the same old in a slightly new, smelly bottle. The script seems stuck in the early 2000s, and it doesn't come across as anything remotely current or enjoyable.
The height of comedy sophistication are the butt bombs that the Ricky Gervais voiced dog drops to thwart pursuers. Add to it vomit jokes, poop jokes and a whole lot of other silliness, and it seems like the franchise has regressed to appealing to only kindergarteners. Nothing here even tries to speak to the 9-10 year old children that the film's stars belong to.
That is not to say the film is without any merit - there is a cast of actors, which, though mostly wasted, is always reliable, and they make it easy to coast along here as well. The character design for the gadgets and villains is a little retro, but extremely visually interesting.
The gimmick that falls the flattest is the scratch and sniff card that the 4D customers get. This is ostensibly to smell the various foods in the film, though they all smell vaguely fruity to me.
Ultimately kids' entertainment has become very sophisticated these days, with animated features exploring big themes and favouring a slightly mature tone over pandering to poop jokes. The newest Spy Kid has no interest in that, and as a consequence, feels dated and out of time (see what I did there?).