In David Mamet and Alaric Jans’s 1977 kids’ play, a Waukegan 12-year-old and his pals Bob (a sheep) and Viv (a girl) journey to the planet Crestview (so named to increase its real estate value). When Crestview’s ruler and his panda patrolmen try to turn Bob into a letter sweater, the earthlings must evade capture and return home in time for lunch. The script and songs balance childlike silliness and wry adult wit, and director Steve Scott’s slick production features especially good performances by Eric Slater as Bob and Kevin Theis as a ham actor who comes to the heroes’ rescue. But blaring sound and elaborate effects (including a flying pumpkin) undercut the comedy’s raffish charm. Through 4/22: Sat 10 and 11:30 AM, Goodman Theatre, 170 N. Dearborn, 312-443-3800, $8-$15.