“I feel silly!” says Ollie (Andrew Wassenich), the adenoidal sidekick of Kid-Simple’s main character, and you gotta empathize with the kid: He’s freak-dancing with a drag-queen satyr sporting rhinestone-encrusted hooves, shag-carpet haunches, and a feather-duster tail as he makes this announcement. There is a great deal of silliness in Forum’s staging of Jordan Harrison’s multimedia fable, and some of it, especially in the early going, is playful and smart, because the cast seems to be daring the audience to take any of this happy nonsense seriously. High school science-fair whiz Moll (Maggie Glauber) invents a device capable of hearing the unspoken and uncanny: the groans of load-bearing walls, the jungle-cat roar of poor Ollie’s pent-up libido. The deadpan descriptions of these impossible sounds projected above the stage are a lot of fun, and so is watching them brought to life by an onstage Foley artist (Scott Burgess, also the show’s sound designer). Fiona Blackshaw, all hauteur and finishing-school vowels as the plucky heroine of a classic radio melodrama, strikes exactly the right tone. But there are plenty of moments where the timing’s off, however, like that goat-man scene, which makes the onstage antics feel self-consciously outsized. Kid-Simple vacillates between being smart and silly—between being about the act of storytelling and being about nothing but its own overwrought mythology (something to do with sinister ancient presences lurking in a preternatural void, their shape-shifting interlocutor, and a magical cello). Most frustratingly, moments of real inventiveness occur amid the usual “experimental” tropes—narrator loses control of the tale, walls between the play’s separate stories crumble. Director Jessica Burgess throws a lot of stuff against the (fourth) wall, but not much ends up sticking: The script’s wordplay gets lost amid the tumult, and once the proceedings become loaded down with portent and allegory, the show never recovers. At an early showing, the cast and crew were still slightly overmatched by Harrison’s script, which admittedly is a logistical ball-buster: The play’s Byzantine network of sound, dialogue, and projection cues demands absolute technical seamlessness, and the seams showed. As a result, several jokes that should have worked didn’t. With some tightening, Kid-Simple will become faster, funnier, and less self-conscious. The ending, however, still won’t make any damn sense.