Bat Boy: The Musical is a joyful curveball of a programming decision by the Southwark Playhouse: a classic Beauty and the Beast (sorry, Beauty and the Bat Boy) story, dressed up in trashy B-movie Gothic style, with a fantastically catchy rocky soundtrack.

In this cult musical, the Bat Boy is found in a cave, brought into a suburban American household and taught to fit in to society. But his natural vampiric impulses cannot be overcome and tragedy ensues. Dues must be paid by this musical to Tim Burton’s Edward Scissorhands, but it still stands alone as a fabulously oddball social critique and a real musical theatre treat.

Appropriately, this production takes itself only as seriously as it absolutely has to, and there are wonderful moments of transparent theatricality such as the use of dolls on strings to represent spelunking teenagers. But in places where it feels as though the production really could have gone all-out, there always seems to be that extra bit of choreography, characterisation, or stagecraft, lacking.

The score is maddeningly catchy, interesting musically with wickedly sharp lyrics, and will have you searching, sadly in vain, for a soundtrack on Spotify. Unfortunately the levels in the show sometimes render the lyrics inaudible, which doesn’t matter so much in a Lloyd Webber, but here it often means missing out on something really good. On the same theme, the raised portion of the stage is sadly underused, while much of the performance takes place close to the ground, meaning that much of it is lost to anyone beyond the third row.

Although the central family are well painted, the extra effort of characterisation hasn’t been paid to the ensemble of townsfolk. The cast give funny, accomplished and energetic performances, but in the end are left little more than screeching caricatures.

Rob Compton as the eponymous Bat Boy is undoubtedly the star of the show. He mediates his intimidatingly muscular physique with heart-breaking vulnerability, performing with enormous physical skill and total emotional conviction throughout. His relationship with Lauren Ward as his adoptive mother is equally truthful, and Ward absolutely makes the most of her complex character as well as all the comedy that the role affords. Special mention must also be made of Simon Bailey who momentarily steals the show as Reverend Hightower, leading the absolutely riotous opening of the second half in a frenzied gospel parody of faith healing.

The production captures the deliberate trashiness of the show, while demonstrating some skilful innovations such as the use of pre-recorded video with live voiceover. It’s worth seeing just for Compton’s performance alone, but the excellent cast and wonderful book make this a fantastically fun, if flawed, cult horror love story.

Bat Boy: The Musical is playing at Southwark Playhouse until 31 January. For more information and tickets, see the Southwark Playhouse website. Photo by Gary Lake.