The animation strives for 1950s sci-fi retro, but the result is that everyone looks like a plastic anim doll.

What might have been a bland Back to the Future rip-off suddenly hums with a screwball sensibility chockablock with singing gangster frogs and evil bowler hats.

Whether you see this loony, feel-good comedy in 3-D or in regular vision, it's a lot of fun.

Both one of Disney's most moving and entertaining efforts, the film is one of the rare near-flawless outings for the studio.