“Whatcha gonna do about it?” One of the audience members puts it straight to Jack McNally, proprietor of McNally's-by-the-Sea, a rundown family hotel whose loyal patrons have finally abandoned its creaking walls. This hotel is the 'house' that Jack fills with imagined guests, in the latest collaboration between Theatre Lovett and Tasmania-based playwright Finegan Kruckemeyer, a name so good you couldn't make up. (Could you?) Just 30, Kruckemeyer has won heaps of awards for his plays for family audiences, which have been performed across five continents.

Seeking to reprise the massive success that was their production of Kruckemeyer's The Girl Who Forgot to Sing Badly (2010, co-commissioned with the Ark), Theatre Lovett has reassembled much of the same artistic team here – Carl Kennedy on sound, John Comiskey on set and lighting design – but this time under the direction of Muireann Ahern, who brings long experience in directing, producing and programming theatre for children and youth. And, of course, returning centre-stage is the irrepressible conjuror of shapes and forms himself, Louis Lovett, as the well meaning but hapless Jack.

The action begins with the entrance of a large flipper through the hotel drapes, followed by Lovett in a snorkel, brandishing the second simulated vacuum cleaner of this year's Dublin Theatre Festival. (Theatre Lovett and Pan Pan in shared device sensation!) Jack introduces himself and his hotel to the audience, before assuming the guises of the various guests. From a fairly convincing soprano to squelching through the muddy flats of the river bed, Lovett is a master shapeshifter – the smallest change in posture and he becomes someone else.

There is the moustachioed Esteban, his Iberian passion for lovely Irish girls played out on his accordion; and Norma and Dorma, the Italian sister divas, all fluttering fans and skittish arias. There is lisping Lionel and his anorak interests, perhaps less funny than he is unnervingly odd; and Mr Truro, former star of the silver screen and maestro of the spoons – cue the reconstruction of a silent movie, supported by able assistants from the audience and some neat lighting tricks. (The illusion works brilliantly if you can shelve your self-consciousness and handle the imaginary camera under your chair.) And there is the love whose name Jack dare not speak, the lovely Mel–.

Just as we are beginning to wonder where all this is actually going, day breaks over a bleak and muddy vista: the river has been drained by the building upstream of a brash super-hotel by Jack's ruthless developer brother and nemesis, Jake. With no scenic vista to enjoy with their full Irish in the mornings, the guests check out, and nature's creeping fronds gradually reclaim the hotel. It's not looking good for Jack and his hotel.

Designer John Comiskey has created an elaborately detailed lobby of an old-fashioned hotel, attractive in its wood and wallpapered distress, with lampshades tilting upwards like blossoms towards the light, and flaps and doors providing for exits, entrances, shadow puppetry and lots of comedy slaps and bangs – but it's a set which leaves very little space for imagination to illuminate, and acts to hem in Lovett at times.

A few other threads fray. It's McNally's by the Sea, except it's a river – which is necessary for the plot, but doesn't quite explain the rolling waves of the soundscape (unless this is what the snorkelling was about); some intricate props – a miniature hotel in a suitcase, a toy train on a brace – seem a lot of effort for only the briefest of appearances; and the arrival of Jake, Jack's brother, quite literally reduces one scene to toilet humour.

These small points aside, The House that Jack Filled is laugh out loud funny and entertaining, due in the main to Lovett's animation of Kruckemeyer's wacky script, as directed by Ahern, in which a judiciously placed pause in a chef's patter about a pig (while spooning chopped carrots into an upturned lamp) brings the house down. Despite having so much to achieve in 75 minutes, Lovett maintains a remarkable flexibility to interjections from the audience: a call from 'Lionel' for a show of hands in favour of his invention establishes early on that the younger contingent towards the front are smart, funny and unafraid – unlike the elders hiding in the darkness up the back.

While there is a happy ending for Jack, and one for his hotel, there is no such denouement for the muddy ecological disaster beyond the hotel terrace, which seems to have been forgotten by the end – this feels like an opportunity missed given the highly engaged audience in an otherwise fun family theatre show.

Fíona Ní Chinnéide is Reviews Editor of Irish Theatre Magazine