Alvin learns to grow up in Alvin and the Chipmunks: Chipwrecked, but maturity remains an alien concept to this CG song-and-dance franchise, which in its third installment, flails about in search of a creative reason to exist. On a cruise-ship vacation, Alvin (Justin Long), brothers Simon (Matthew Gray Gubler) and Theodore (Jesse McCartney), and their female doppelgangers, the Chipettes, become stranded on a deserted island, prompting not, alas, a to-the-death Lord of the Flies scenario but, instead, merely a perfunctory rescue mission from paternal owner Dave (Jason Lee) and bird-costumed former nemesis Ian (David Cross). In the wild, Alvin embraces responsibility, and Simon (transformed by a head-conk) becomes carefree and confident. Nonetheless, there's barely a narrative to speak of in director Mike Mitchell's slapstick-y adventure, which is mainly concerned with haphazard movie references (The Lord of the Rings, Castaway) and grating Chipmunk-ized renditions of hits by, among others, Willow Smith and Destiny's Child. Smushing together Katy Perry's "Firework" and Lady Gaga's "Born This Way" in a tossed-off finale would be more egregious if it -- like a fittingly lame nod to the "Double Rainbow" viral video -- didn't perfectly epitomize Chipwrecked's unimaginative pandering to contemporary top 40 and pop-culture fads.