Sometimes improv feels banal: we've seen these games before and heard all the tired, often boringly dirty audience suggestions. But this warm, abbreviated version of ComedySportz's regular improv antics is a joy--a fresh, spontaneous collaboration between adults and kids. Tweaked for the 5- to 10-year-old set, it features a "referee" and three "team members" from a rotating cast who invite kids onstage to play improv games, like a version of Mad Libs. There's also a musical created through audience suggestion. (Our title: "The Evil Doorbell.") Sure, the improv is sharp, but what really makes this production is the way it showcases kids at their best: creative, funny, silly, full of energy. Open run: Sat 2 PM, no show 12/24, ComedySportz, 2851 N. Halsted, 773-549-8080 $5-$10.