Gently does it, as Chris O'Dowd's imaginary friend helps cute little Martin Moone through more childhood challenges in this cockle-warming tale. This week, there's a trouser incident after wide-eyed Martin watches one too many TV shows involving "grunty Argentinian tennis ladies". Sean (O'Dowd) is too busy enjoying a night at the pub with fellow fantasy figures including the legendary wrestler Crunchy Haystacks (Johnny Vegas) to offer Martin much-needed advice. Luckily, Uncle Danny the busker arrives home with wise words and tales of hanging out with U2. Subtle laughs all round.

Chris O'Dowd on Moone Boy's tight budget

"Moone boy had such a tight budget I had to change in the loo and stay at my parents".

Chris O'Dowd's comedy possesses that rare thing: warmth. His characters are as likeable as their exploits are amusing. Our young hero is mortified when he arrives at school looking like a pre-pubescent drag queen; his sister has painted his face overnight. Mam has no sympathy: she's too busy starting her new career as a weight-loss instructor. So he consults his imaginary friend (O'Dowd) and resorts to drastic measures to ensure he never has to endure humiliation again.

Martin (David Rawle) wakes up, doesn't bother to wash his face and thus fails to avoid falling victim to one of his sister Sinead's pranks. A prank that leaves him wandering into school caked in more make-up than Widow Twankey. What to do? Why, break down the wall at the back of his house to shorten his commute, and thus allow more face-washing time in his morning routine. Naturally - after all the Berlin Wall happens to be coming down at the same time. There's a gentle sense of whimsy to this third episode of Chris O'Dowd's sitcom, which means that, while it's not exactly packed with belly laughs, it's nonetheless a sweet, enjoyable way to while away half an hour. Then again, it's hard to go wrong when your lead character is such a cherubic little kid.

Based on Chris O'Dowd's experiences growing up in Ireland in the Eighties (and filmed in the town he grew up in), Moone Boy is - theoretically at least - a slightly risky proposition in some respects. For one thing, it exploits a private nostalgia for a public audience (and nostalgia can easily get self-indulgent). For another, it employs a lot of child actors, which can be tricky when it comes to comic delivery. In practice though Moone Boy is entirely lovable, one of those comedies that you actually feel a slightly better person for liking.

The comedy is centred around Martin, a young boy growing up with three unrelentingly scornful sisters (Trisha, Fidelma and Sinead) and taking refuge in doodled cartoons and the comforting presence of an imaginary friend, played by O'Dowd himself. Martin is bottom of the pecking order at home and not much higher at school, but he has a resilient can-do perkiness that appears to carry him through (and which can, if one's absolutely honest, sometimes be a tiny bit off-putting). If the comedy was only about him it wouldn't work anything like as well (the alter ego device doesn't deliver as big a pay-off in laughs as you might expect). But it diverts in quite unexpected ways. In the first episode, for example, a run-in with the school bullies triggered a lovely running joke about Irish manhood. Confronting the father of the bullies, Martin's dad is startled to encounter a paragon of sympathy instead of a brute ("Oh no! They're awful aren't they?"). He then finds himself enlisted to a secret self-help group for the town's patriarchally challenged.

The comedy of childhood is nicely done, too. Faking a love letter to his sister as part of a complicated deal to enlist the protection of the school's tough guy, Martin searches for the highest praise he can think of and comes up with "you smell nicer than crisps". But it's the sense of the family and community around him that really makes the thing work. In the second episode of the opening double-bill, Martin's mother came to the fore, campaigning with other women in the town to get Mary Robinson elected to the Irish presidency. "I won't vote for her for President," says one of the women they canvass, "but I'll vote for her to be the President's wife." And Steve Coogan - whose company Baby Cow makes the programme, appeared in a very funny cameo as a notoriously gropey local plutocrat. It's sweet-natured, fresh and absolutely not by-the-numbers, and if you want to bully it you'll have to get past me first.

Martin Paul Kenny Dalglish Moone is the most life-affirming delight to have hit our screens in a long time. Played with gap-toothed genius by young David Rawle - actually he doesn't have a gap-tooth but the charm of the writing somehow makes you think he does - he's the amalgam of every well-intentioned, bright, troubled 12-year-old you might have been lucky enough to meet, and somehow manages to span every shade of the above category, from Thomas Turgoose's darker character in the Shane Meadows things, via every Roddy Doyle 12-year-old, ever, to Nicholas Hoult's Marcus in the more glucose-rich About a Boy.

Which is possibly to imbue Rawle's success with heavier pretensions than the writing would ever affect: Moone Boy is, essentially, a piece of fun. But what fun. Written by Chris O'Dowd and Nick Vincent Murphy, it's the tale of Martin Moone growing up in Boyle, County Roscommon, in the teeth of 1989 - we're told this by the scrolling title in the first scene, along with the nugget: "Chance of rain, weirdly low." So far, in Boyle, so Doyle, and this is not so much of a bad thing, as Martin copes with bullies, his mother's feminism, his sister's bras, broccoli boiled until it turns white, and the like, though it has (so far) stopped short of a horse in a lift. Where this is lifted superbly is in the appearance of Martin's thirtysomething be-beanied "imaginary friend", played by O'Dowd, who appears as a one-man Greek chorus, with banjo, to offer Martin the worst advice imaginable at every turn; and the occasional animations as we are taken inside Martin's head and reminded of the vaulting imagination you're stuck with by virtue of being 12 and clever.

It is surreal, within decent limits, and it is derivative, but I think the derivations are happily if tacitly acknowledged; musically, certainly so, as we get stings from Grange Hill, Mission: Impossible, Raindrops Keep Fallin', etc. There are grand twists, such as the disenfranchised, underemployed menfolk - including Martin's lovely dad Liam and the bullying twins' father - meeting up for ostensible poker schools or fishing trips (none of them own fishing rods, or even a pack of cards) but instead to drink and moan, with their damp-eyed remnants of manliness, about the impossibility of all their children. If the opening two episodes, also featuring a forgivably OTT cameo from Steve Coogan, are representative, there's a granite-solid winner here, sculpted with charm, knowingness and a canny ability to lift from tradition while delivering fresh unpredicatability at every turn. Sky has been waiting for a return on its huge investments in new comedy; and of course Ireland has been waiting too long for anything to even approach Father Ted: early days, but I think that if these are boxes which needed ticking, and the boxes could somehow be painted glass panels awaiting some pebbles from a cheeky 12-year-old, then what we're hearing here is the happy sound of breaking glass.

There are cartoonish capers in this new series, Moone Boy. It's also co-written by its star, Chris O'Dowd - formerly best known for The IT Crowd, now popping up in Hollywood movies all over the shop. Moone Boy is based on his upbringing in a small Irish town, but this ain't exactly a misery memoir. O'Dowd plays the imaginary friend of Martin Moone (David Rawle), a 12-year-old living in Boyle in 1987, and what japes they have! Moone Boy is as bright and uncool as the pair's matching red bobble hats, as upbeat and mildly irritating as its theme music, Sultans of Ping FC's "Where's Me Jumper?".

The plot is slight; Martin is bullied by the Bonner brothers, so he seeks protection from a bigger bully, who agrees - in exchange for a feel of Martin's sister's boobs. What's odd, though, is that O'Dowd's character isn't really used for anything - he seems to be there mostly to provide voiceover, and to play banjo to block out the swearwords when Martin's sister goes on a foul-mouthed rant. It's one of many elements that make it feel like children's programming, the final slot on the CBBC schedule; with jaunty animated sequences and rapid editing, Moone Boy is a bit Beano. Presumably meant to be nostalgic, sweet entertainment for adults, it's perhaps too successful at inhabiting the kidult mindframe.

Malcolm Tucker may have been back in The Thick Of It on BBC2 last night, but the comedy highlight of the week was Sky1's new Friday night delight Moone Boy.

It's a warm, nostalgic Irish tale starring Chris O'Dowd as Sean Murphy, the imaginary friend of 11-year-old Martin Moone, who is brilliantly played by David Rawle.

But guest star Steve Coogan stole the show early as Francie Feeley, a rich, loud-mouthed, hard-drinking big shot with a reputation for being rather too friendly with the local ladies. Hardly much of a stretch for Coogan, you might say, given his own past. But hey, those Irish accents can be quite tricky to pull off sometimes.

Chris O'Dowd interview, Moone Boy

Chris O'Dowd takes a break from Hollywood to return to his roots in Sky1's new comedy Moone Boy.

You'd never guess that IT Crowd actor Chris O'Dowd was now hobnobbing with the likes of Judd Apatow and Jack Black judging by this charming little comedy based on his inauspicious upbringing in late 1980s/early 1990 Ireland. It was born from the Little Cracker short that O'Dowd wrote for Sky1 in 2010 and sees him play the imaginary friend of 12-year-old Martin Moone (David Rawle), a boy who spends his days drawing, formulating crackpot schemes and generally trying to negotiate life with his scatty family.