A garden snail feels the need, the need for slime-burning speed in David Soren's heart-warming computer-animated adventure.

Following a tried and tested formula that propels the film into the winner's circle (albeit without any surprising detours), Turbo is a classic David and Goliath story enlivened with larger-than-life characters and high-octane action sequences.

The script written by Soren, Robert Siegel and Darren Lemke is simplistic, particularly the relationship between Turbo (voiced by Ryan Reynolds) and his snail sibling Chet (Paul Giamatti), who insists on casting dark clouds of doubt over the diminutive hero's dreams.

"All these people believe in me, why won't you?" implores Turbo.

It doesn't take a genius to conclude the brothers will be reconciled beneath a fluttering chequered flag to enforce the message that anything is possible if you work hard and stay true to yourself.

When we first meet Turbo, he is toiling in the tomato patch with his ultra-cautious worrywart brother. Unlike his fellow molluscs, Turbo has big dreams: he yearns to put a pedal to the metal like his hero - French-Canadian Indianapolis 500 champion, Guy Gagne (Bill Hader).

So Turbo trains hard, managing to slither the distance of a standard ruler in... 17 minutes.

"This is a new record!" he whoops.

Outrageous misfortune sucks Turbo into the engine of a street-racing car and the snail is coated in nitrous oxide, which fuses with his DNA and allows him to perform bursts of death-defying speed.

Turbo becomes the star attraction at mollusc races organized by taco truck driver Tito (Michael Pena) at a rundown strip mall on the outskirts of town.

"This snail crashed into our lives for a reason. I think he might be our little shooting star!" Tito excitedly tells his brother Angelo (Luis Guzman).

So the truck driver exploits a loophole in the rules of the Indianapolis 500 and enters Turbo alongside Gagne.

Supported by the other racing snails - Whiplash (Samuel L Jackson), Smoove Move (Snoop Dogg), Burn (Maya Rudolph), Skidmark (Ben Schwartz) and White Shadow (Michael Patrick Bell) - Turbo risks everything to defy Mother Nature and out-manoeuvre his arrogant idol.

Soren's film is harmless and wholesome family entertainment, punctuated by racing sequences that shift our pulses up a gear.

The title character is instantly likeable and we root for Turbo as more obstacles are flung in his path. Snails have rarely looked so gosh-darn strokeable.

Reynolds radiates warmth in the lead opposite a suitably downbeat Giamatti, with supporting cast dividing up the one-liners as the comic relief including Ken Jeong as a sassy manicurist. Visuals are slick, even at high-speed, but lack some of the intricacy and minute detail that have set Pixar films apart from the pack.

Turbo puts up a spirited chase but doesn't quite have enough original ideas in the tank.