Accents in films can be a tricky thing. It seems, on the surface, so inconsequential to a film - but oftentimes, the rest of the film's marvels and delights can be overshadowed by a horribly misjudged accent. Far And Away, for example, had Tom Cruise's mangled Oirish accent distracting people from gorgeous visuals and a heartwarming story of immigration and a new frontier. Although The Walk isn't up there, or down there as the case may be, with Far And Away, Joseph Gordon-Levitt's accent is so atrocious as to be truly grating.

For those who haven't seen the eminently superior, Oscar-winning documentary Man On Wire, the plot is straightforward enough. Phillipe Petit is a career tightrope walker, clown, mime and all-round performance 'artiste' who becomes obsessed with one thing - running a wire between the Twin Towers and walking across it. From the very beginning of the film, Petit's narration tells us that two things: he's a natural performer who lives to astound people and he's pretty much nuts. We're given a rudimentary overview of his early life; parents unwilling to see his 'vision', running away to join the circus and meeting his mentor played by Ben Kingsley before he arrives in Paris where he meets love interest Charlotte Le Bon. From there, it's a hop-skip-jump to New York where he begins to pull off his so-called coup.

For the most part, Levitt's performance is well-matched to the real-life Petit. Those who have seen Man On Wire will know that he's more than a little eccentric, which Levitt cleverly manages to channel without it becoming a straight impression. Likewise, he's captured the mannerisms and visual tics of the character so that, for the most part, they're one and the same. Where it all goes horribly, horribly wrong is the accent. It's so clearly forced as almost become a stereotype. It's really, really that bad. You're almost expecting Levitt's character to walk onto the screen with a beret, cigarette hanging out of his mouth and a string of onions around his neck.In fact, the accent is so bad, it's distracting. The consistent narration pulls you out of key scenes and doesn't allow them to breathe in a natural way.

Director Robert Zemeckis' penchant for CGI effects hasn't gone away. As we know, he spent several years creating CGI-only films (Beowulf, The Polar Express) and has now, finally, returned to the land of the living. It's evident to see why Zemeckis chose to make this film. He literally has to rebuild the Twin Towers from scratch as the second half of the film is set entirely there. With Le Bon and Levitt, co-conspirators James Badge Dale, Ben Schwartz and Steve Valentine stage their break-in and it's here that the film begins to pick up pace. Although the supporting cast falls in behind Levitt's shadow, they're given a few moments to shine here and there; primarily as comedic relief during the film's tenser moments. Le Bon, in particular, acts as a decent foil to Levitt's unhinged ramblings. James Badge Dale, meanwhile, acts as the smooth-talking New Yorker whose expert blagging gets them in the Twin Towers with ease.

For the most part, The Walk is affecting, if sugar-sweet in earnest. There's a real sense of optimism and confidence about it that's comforting. Zemeckis, however, made some odd choices in both the story and how he told it - particularly the narration. Putting Petit's storytelling front and centre almost begs us to compare it to Man On Wire, which used a similar tactic. When we compare Man On Wire to The Walk, it's like the difference between night and day. Where the documentary set it up as an expert, daring heist, The Walk sees itself more as a joyous, earnest retelling of events. It doesn't lack for confidence, but more often than not, we can see the wires keeping it altogether. The finale is undoubtedly the best part and Zemeckis shows an adeptness with fusing CGI with practical effects not seen in years. Here, we see the pay-off for the hackneyed 'struggle to realise his dream' segments at the beginning and the somewhat clunky middle section.

In all, it's a reasonably entertaining biopic with enormous heart. It's just a shame that Levitt's horrific accent will be more frequently remembered than the film itself.