There's nothing really wrong with "Turbo," a cute story of a plucky snail who aspires to be a racer. It's just that there's nothing to this DreamWorks Animation adventure except pleasantly formulaic storytelling and predictable follow-your-dreams sentimentality.
Theo (voiced by Ryan Reynolds) works with his fellow snails in a tomato garden, waiting for the overripe fruit to drop while they avoid such dangers as passing crows, lawn mowers and a Big Wheel-riding kid nicknamed "The Shellcrusher." Theo, being the hero of an animated movie, wants something more in life. He wants to be a racer, even if his top speed in the one-yard dash is 17 minutes.
Then, as fate (and screenwriting shortcuts) would have it, Theo, who prefers the nickname Turbo, lands atop a street-racing car, gets sucked into the engine and is hit with a blast of nitrous oxide. And, like Peter Parker getting a radioactive spider's bite, Turbo's DNA is altered so that he can zip along at 200 mph and higher.