Disney's latest animated feature can't quite overcome the sheer flimsiness of the conceit on which it is built. Ralph (voiced by John C Reilly) is a villain in an old video game in an arcade. He is sick of being the baddie.
To prove he can be a hero, he leaves his own game and sets off on an epic journey into other computer game worlds. It's a feeble starting point but – as you would expect in a film exec produced by Pixar's John Lasseter – a huge amount of ingenuity has gone into the characters and 3D animation.
Much of the film unfolds in Sugar Rush, a go-karting game where the landscape is built of confectionery. Here, Ralph befriends a tiny tomboy (Sarah Silverman) nicknamed a "glitch" because she doesn't really exist as a full computer character.
The film tries hard both to be nostalgic, evoking a Pac-Man-era world of lost innocence, and contemporary, nodding in the direction of Call of Duty-style war games.
There are some rousing chases and races but we are always aware that the characters are one-dimensional figures from ancient arcade games. The mawkishness is as cloying as the gloop that Ralph encounters on his journey across Sugar Rush.