Blue Sky Studios' latest feature, Rio, isn't a particularly clever or memorable animated film, but it does at least finally settle the debate as to why the animated genre resonates and endures so heartily, and why similar films employing live action most often fail. The charm isn't really in the talking animals or the silly characters - though they surely help - but the visual thrill, and in CGI-live action mish-mash fare like Cats and Dogs, this promise is lost in the uncanny, clunky mixture of the two. Blue Sky Studios smartly don't venture into the awkward gray area of live action as must be tempting for a film of this nature, and instead stick to the tried and tested success of full animation. While they may have crafted here a film more alike their Robots than their Ice Age, its striking visual appeal is undeniable, and though this may be enough for kids, adults can expect to start shuffling by half-way. For all Rio gets wrong as a derivative anthropomorphic-animals-on-the-run movie, it is superbly cast; Jesse Eisenberg's awkward, staccato-style voice lends itself wonderfully to the animated form as Blu, the inept Spix's Macaw who hasn't yet learned to fly. His owner, Linda, voiced with enthusiasm by Leslie Mann, is informed by bird fanatic Túlio (Rodrigo Santoro) that Blu is an incredibly rare bird, and must mate with the other remaining member of his species, Jewel (Anne Hathaway, who seems able to juggle just about anything and doesn't disappoint here), in order to repopulate their species. Naturally, along side the clashing personalities of the bashful, clueless Blu and sassy, assertive Jewel, all manner of adventure hijinks ensue - clumsy thieves, downtrodden street kids with hearts of gold, and an elaborate parade to end it all. While it's all been-there-done-that caper shtick, at least the filmmakers had the good sense to populate the film with robust voices the likes of Jane Lynch, Neil Patrick Harris, Wanda Sykes, Jamie Foxx (particularly good as a Canary who wears a bottle cap as a hat), and think what you will of him as an actor, Tracy Morgan's slobbering bulldog character, Luiz, is sure to get a constant giggle out of the kids. However, Rio is difficult to watch without imagining it was a light bulb idea bandied around the office of the Rio de Janeiro Tourist Board; the film positively takes advantage of its setting, capturing both the gritty slums and the majestic sights (naturally, Christ the Redeemer), yet there's no escaping the air of mediocrity which envelops the whole affair thanks to a sub-par screenplay, largely bereft of wit and instead content simply to evoke a smile here and there. Characters are pure archetypes, and while this isn't uncommon in the animated field - geeky lovebirds Linda and Túlio instantly remind one of Flint and Sam from Cloudy With a Chance of Meatballs, who in turn remind us of about a dozen couples from live action fare - the charm and intelligence needed to make it more than breezily appealing just isn't there. Naturally, we're typically spoiled when it comes to animated films these days, thus a low score doesn't necessary suggest it won't keep the most nascent children entertained briefly. Still, for kids reared on Pixar and Dreamworks, and even the Ice Age films themselves, this will likely come as a disappointment; the songs lack conviction, and though the visuals crackle and the 3D is solid, the splendid voice actors never get the full thrift they deserve. It's difficult to imagine many emerging from Rio remembering much more than the gorgeous scenery; this is pure, animated bubble gum for the eyes and little else, despite a refreshing lack of big issues to deal with. Rio is released in cinema's from tomorrow.