Say what you will about London theatre during 2015, and by my reckoning it was a pretty fine year, there certainly was a lot of it. I can't recall a year that brought with it a comparable volume of openings, not least during September and December, this year's pre-Christmas slate of major press nights roughly double the same time period in 2014. And as proof that people were actually attending the stuff on offer, empirical evidence as ever was the best guide.

North Korea is the kind of place that haunts the imagination of the West – and not in a good way. One of the last hardline Communist dictatorships, it is also a country of immense sadness, a landscape of food shortages and human-rights abuses. Yet its regime calls this dismal place the "Best Nation in the World". To us, it’s a secret world, a strange culture difficult to comprehend, easy to fear. Small wonder that, in American playwright Mia Chung’s 2012 play, two hungry sisters fantasise about leaving it for good.

Don’t you just love celebrity hype? Kim Cattrall’s name alone sold out this show, which runs over the notoriously difficult Christmas period. But sometimes star-casting backfires, and when she had to withdraw from the production for medical reasons, the theatre had to find a replacement. Step forward Noma Dumezweni, an Olivier-award-winning performer who’s due to make her directing debut at this venue next February. But that’s enough, for the moment, about celebrity – what about the writer and the play?

Once upon a time, quite recently, you couldn’t move for plays about youth. Now, there’s been an avalanche of dramas about ageing, usually in the context of dementia and family life. Maybe all of our main playwrights have suddenly grown up, or maybe the endless quest for novelty has deposited us on the shores of the current trend-setting idea. Nicola Wilson’s Royal Court debut is yet another play about Alzheimer’s, ageing and memory, but is it any different from Florian Zeller’s The Father, April de Angelis’s After Electra or Emma Adams’s Animals?

Welcome back Martin McDonagh. It’s been more than 10 years since you’ve had a play on in London, and I was beginning to think that we had lost you to Broadway, and Hollywood, for ever. As you know, I loved it when your Leenane Trilogy burst onto our stages in the late 1990s, and although I wasn’t that keen on some of the follow-ups, your The Lieutenant of Inishmore (2001) and The Pillowman (2003) are among my favourite plays.

When is a monologue not quite a monologue? When it is interrupted by another voice, one that contradicts and argues with it. In Cordelia Lynn’s Lela & Co, her Royal Court debut which is effectively and savagely staged in the claustrophobic heat of the upstairs studio space, the drama starts off as a classic monologue, with Lela telling the story of her life, starting with her birth. Then she tells of her rather brutish upbringing up to the age of about 15.

Once upon a time... Storytelling is an integral part of all human cultures, and a central pillar of an enlightened education. Some children get the hang of it quickly – they are, as the phrase has it, natural storytellers. This week the Royal Court introduces several youthful writers with Primetime, a series of short plays written by primary school children between the ages of eight and 11.

Life, the universe and everything… in 70 minutes. You certainly can’t fault Nick Payne’s ambition, nor help but admire the dazzling inventiveness of his theoretical physics romcom with a side helping of artisanal beekeeping.

The latest transatlantic transfer is curiously esoteric, concerning as it does an obscure period in the lives of two great men: Laurence Olivier and Orson Welles. The centenary of the latter’s birth makes this an apt moment for the European premiere of Austin Pendleton’s Chicago-originating 2000 play, but its appeal may not extend beyond dedicated students of theatre history.

One of the most talented playwrights to emerge in the 2000s, debbie tucker green is a law unto herself. The best word to describe her is uncompromising. When I interviewed her in 2003 she refused pointblank to answer any questions about her West Indian background and since then she has steadfastly declined to discuss her work in the media. Like Caryl Churchill, she doesn’t do publicity. So that just leaves the work, which is always provocative, original and written in an unmistakable voice.