After the Hotel Transylvania films and Scream Street, you might be forgiven for thinking the market for children's animations about amiable monsters well cornered. Despite the name voice cast, Sky Cinema's home and cinema release offers few reasons to reconsider. Good-looking but erratically plotted and unfunny, director Holger Tappe's adaptation of David Safier's book Happy Family lands with a thud more deadening than the footsteps of Frankenstein's Monster.

The only thing flatter than its gags is the singing voice of Jason Isaacs as a crooning Count Dracula, whom we meet as he vamps it up in a leather onesie and pines for love. When harassed New York mum Emma Wishbone (Emily Watson) gets Drac's teeth tingling, he orders witch Baba Yaga (Catherine Tate) to turn Emma into a vampire. But Baba also curses Emma's dysfunctional family with monster makeovers, posing the following problem: can Emma's flatulent husband Frank (Nick Frost), brainy son Max (Ethan Rouse) and sulky daughter Fay (Jessica Brown Findlay) stop bickering and band together to lift the curse?

The resulting romp wants to be The Incredibles with fangs, but Pixar didn't load up on fart gags to hide deficits of wit. Despite the work of six writers (fronted by Safier and Catharina Junk), the gag-starved script leaves seasoned comic pros Tate and Frost nothing to bite down on.

Focus proves equally elusive. Like a mummy losing its bandages, the busy plot lurches messily between New York, London, the desert and Drac's man-cave, piling up sub-plots about bullies, models, pharaohs, hippie bookstore employees and more on its way. All that's left for the climax to cling to is a few under-earned messages, including Fay's realisation that looks matter less than what we are inside. Pity there's so little going on under Monster Family's own glossy surface.

Screening on Sky Cinema and theatrically from Fri 2 Mar.