After the stiff attempts at realism in many recent features, it's a treat to see broad cartoon-style animation on the big screen in Osmosis Jones, a spoof of cop movies set inside the human body. The title character (voice by Chris Rock) is a street-smart white blood cell, working for Frank's immune system. He and Drix (David Hyde Pierce), an over-the-counter cold capsule, are reluctant partners fighting what appears to be a minor infection. Osmosis discovers Frank has really contracted a fatal virus, Thrax (Laurence Fishburne): he battles a corrupt body politic led by a venal mayor (William Shatner) to save Frank's life and win the affection of the mayor's aide, Leah (Brandy Norwood). Rock's motor-mouth delivery can get annoying, but it contrasts nicely with straight arrow Drix (imagine a fussy Buzz Lightyear). Excellent drawing and a powerful vocal performance make Thrax a genuinely frightening villain.

Osmosis Jones is about two-thirds animation and one-third live action, which is why two-thirds of the film is entertaining and funny, and one-third is not. The life Osmosis and Drix save belongs to Frank, a slob played in live-action sequences by Bill Murray, who's undercut rather than supported by Chris Elliott and Molly Shannon. Shamelessly over-the-top performances make the human characters seem flatter than the two-dimensional cartoons. The live action was shot by the Farrelly brothers and features lots of gross-out gags about zits, flatulence, vomit, etc. The audience endures these leaden segments, waiting to get back to the animation--and the real comedy. Suitable for ages 9 and up: profanity, violence, bodily function jokes. --Charles Solomon, Amazon.com

Chris Cole always wanted to be a rock star and his girlfriend thinks he can make it to the top. He still lives with his parents, when he is not fronting a tribute band, but one day he is fired. Devastated he returns home only to receive a phone call asking him to replace the singer in the legendary heavy metal band, Steel Dragons - the band he has always idolised...