Neither the magic of Harry Potter nor the combined star power of Katherine Heigl and Gerard Butler was enough to keep a crew of wise-cracking guinea pigs from scurrying to the top of the box office this weekend. Disney’s family comedy “G-Force,” produced by Jerry Bruckheimer and featuring the voices of Nicolas Cage, Will Arnett, and Penelope Cruz as a team of world-saving rodents, made an estimated $32.2 million in its debut. Despite opening hot on the heels of the one-week old “Harry Potter and the Half-Blood Prince,” the animation/live action hybrid pic was a hit with young audiences, pulling 55 percent of its viewers from the under-18 crowd.
