If the best children's theater amuses and engages adults as much as children, then Balagan Theatre's world premiere of King Arthur and the Knights of the Playground doesn't make the grade. Still, the kids seemed to love it, and you can't beat the ticket price—free—for the next three weekends in parks around the city.

The story unfolds on the playground of Camelot Elementary, as a group of fifth graders attempt to work out schoolyard tensions by playing at being the knights of the Round Table. More faithful to the free-form nature of childhood imaginative play than to the Arthurian legend itself, the story line skips frenetically between fantasy and playground realpolitik, with Arthur and his knights encountering space pirates, hobbits, robots, unicorns, and unfortunate pants-wettings, along with the more usual Arthurian themes. Much of this clever chaos is by design, though at times it feels more like the uneven product of a marathon improv session than a finished script.

What the play lacks in coherence it makes up for in energy. The ensemble cast is nothing if not enthusiastic (and loud—a big plus given the outdoor setting), and they mostly handle the challenging and exhausting task of the adult-playing-child-playing-adult shtick with ease and charm. Plus, there's plenty of action to keep young audiences engaged, including cleverly staged swordfights, chase scenes, and a slow-motion dodgeball climax between Arthur and his sister Morgan.

There are a handful of lines thrown in for us fogies (mostly references to the original Arthurian legends), and it's a pleasant enough way to spend an hour on a sunny afternoon—but it's the kiddies in the audience, 8 and younger, who'll have the most fun. recommended