Honey's Happening is a lot of fun. It's not the deepest or most subtle piece of theatre you'll see this Edinburgh Fringe, though there's enough of a message in it to balance out the frivolity; what it does feature are utterly loveable characters, some meaningful interactive bits, and a generous serving of knowing retro style. If the heavyweight themes all around us this year are starting to weigh you down, this is the perfect way to cast off a little of that burden.

It's the late 1960's – and among the nation's youth, the scent of rebellion's in the air. Attuned to the zeitgeist, the eponymous Honey stages a "Happening": an open-door party to celebrate humanity, and make her own contribution to the search for world peace. The trouble is, Honey's a middle-aged suburban housewife, and her non-alcoholic punch and easy-listening music aren't quite as "happening" as she believes. Her grown-up daughter Barbara is there to support her… but she's acutely aware of how ridiculous this is, and she can't resist sowing a little subversion.

The comedy is gentle; yes, we're laughing at Honey, but her heart's in the right place and we can't help getting on-side with her. There's a ludicrous moment of attempted hippy spiritualism, and the ongoing promise of a food-based centrepiece (which, when it finally appears, is every bit as spectacular as Honey has led us to believe). Most of all, though, there are party games: funny, unthreatening, entirely non-embarrassing amusements, which tie neatly into the theme of inclusion and have the whole audience joining in. Plenty of Fringe shows let you interact with the actors; this one does something even more rewarding, and invites us to make friends with each other.

It's easy to spot the twist that's coming, but it's not so obvious what will happen once it's revealed. What we get is clever: a neatly logical consequence of the party's unusual set-up, which delivers a big-hearted feelgood message without skating over some undeniable pain. When so many shows this year expose the fractures in society, it's a pleasure to find one that pats us on the back – tells us that, while the world still holds many ills, in some very important ways we're actually doing fine.

Fiona Coffey and Asha Cornelia Cluer make a fine double-act as Honey and Barbara, betraying a hint of sparkiness in their mother-and-daughter relationship yet working together to keep the party bubbling along. The vintage styling is delightful, from the hair and costumes to the retro sideboard – and even the food. Yes, you get food. Only a mouthful, but it's very in keeping with the throwback feel.

Honey's Happening is a genuine treat: a life-affirming hug of a show, which is sure to put a smile on the stoniest of faces. Do yourself a favour, get a ticket, and enjoy.