Totally Spies is one of those shows that's very obviously made for kids. The high-pitched voices, lack of actual violence despite situations that would call for it in reality, and all of the pretty colors make it kid-friendly.
The animation itself is fun, too. Much of it is realistic, and what isn't still manages to be funny and entertaining. I would rate the show as a 10 for its plots (even though some were sort of lame) but I have to give it a 9 simply because many of the situations the spies ended up in were, if the show was geared towards adults, ones that would seriously imply forced sexual situations. But, more than that, this show portrays all three girls as incredibly superficial. While they do pull their act together in time to save the world, you can bet they'll be back to pretentious "deepness" while we wait for the expected shallow-ness to kick in. As a girl, I found myself cringing even as a preteen at many of the ways these girls behaved. If boys take their cue from this show, they'll have no idea how to talk to a real one. I don't know of any real-life girls who act like the spies do, but it *is* a cartoon. Do any of you really expect people to try and take over the world using nail polish, shoes, pizza, or chocolate? If so, maybe TS is *too* mature for you.
All that said, Totally Spies is still awesome. The animation, personalities (the real ones, when they show through) unique plots, and the frequency at which these girls "fall in love" upon spotting a cute guy round out the show in a more positive than negative way. The romance stuff squicks me out a bit even as an adult now, considering it's so appearance-based, but overall, this show is greatly entertaining and fun to watch. :)