Young kids are likely to really like Robots, in the same way they love Barney and adults can't stand Barney. Robots doesn't have the depth of plot or characters you'd expect from a Pixar film, which allow movies like Up and Toy Story to appeal to all ages. Of the many things I could say against Robots, there's only one great sin in my mind when it comes to entertainment: BORING.
Robots is incredibly boring. Despite an all-star voice acting cast that does a fantastic job of delivering the poorly-written dialogue and decent CG animation that provides visual interest, but only until the novelty factor wears off, you completely lose interest in the plot and the characters and even the nifty animation after about 15 minutes. The entire story occupies about 10 minutes of the movie, and the individual plot points dispersed and separated by elaborate, drawn-out sight gags and montages that start off okay, but just drag on and on, and I don't mean in a Seth McFarlane awkwardly long way that ends up becoming really funny. The timing is just off, and the result is pore boredom.
I don't write a lot of reviews, but this is one of those rare films where I was disappointed enough to take the time to warn people not to watch it. Especially parents, don't let your kids watch this. They will love it, and you'll never hear the end of it.