Many of Viola Spolin's theater games were originally created for kids. So there's some justice in the fact that Jerk Alert Productions is using her games to create its fully improvised children's show. During this sweet, charming, energetic matinee performance, kids in the audience are invited to name the characters, pick out their costumes, and from time to time join in the action. The ensemble is remarkably patient with an audience eager to shout out at all times; one loud little tyke even reminded an actor that he'd forgotten his character's name. Most of the show is geared toward children, but the actors do toss in a few sly references that grown-ups will appreciate. Through 10/23: Sat 2 PM. ComedySportz, 2851 N. Halsted, 773-549-8080. $5-$10.