One of the great strengths of London theatre, and arguably its great weakness, too, is that there is far too much of it going on and far too rapid a turnover of product. Many theatres and producers operate on a sort of treadmill, with schedules to fill and not enough good stuff to fill them.

The consequence for critical writing is that the same narrow (well, not that narrow; predictable, perhaps) tranche of work tends to get reviewed in the newspapers, though of course the internet has liberated a site such as this one into virtually limitless possibilities of review coverage.

And the consequence of that, in the wider but still shrinking world, is possibly a big blurred blob of coverage that has no focus, point or discriminatory meaning. Only time will tell, and time will sort it all out, as we go through what I still think of as a transitional phase in all this.

One thing that won’t change is the number of hours in the day and days in the week (not so far as we know, anyway), so all dedicated critics, reporters, bloggers, etc, fight to make room in their lives for the deserving causes that invariably go missing a lot of the time in their schedules.

I woke up last week, for instance, to the fact that I’d not been to the Unicorn for some time, the first purpose-built children’s theatre in London, now under the leadership of Purni Morell, who came recently from the National Theatre studio to succeed Tony Graham, the new building’s first and highly successful artistic director.

She’s already made some interesting changes. The box office has swapped places with the cafe, to good effect. The interior decoration is much improved by some clever lighting and wonderful Quentin Blake illustrations (to be fair, the Blake drawings were already there, but I hadn't taken time to look at them properly).

More importantly, perhaps, Purni is now targeting a much wider range of audience – two year-olds to 21 year-olds, as opposed to the regulation 3-12 year-old category – and she’s keen to reposition the theatre in the wider, broader context of high class innovative new theatre work elsewhere in Britain and indeed Europe generally.

There’s no stigma attached to being a children’s theatre these days; it does seem that, at long last, children's playwright David Wood’s plea for theatre for young people to be placed on an equal footing with all other theatre has been honoured. This season’s Unicorn programme includes new work by Chris Goode, David Greig, Tim Crouch, Oily Cart and E V Crowe, and you can’t say more new and potentially exciting than that.

On Friday, I caught up at last with Crouch’s solo Shakespeare show (his fourth), I Malvolio: it’s an absolute cracker, Crouch playing the derided and humiliated steward in his night shirt, torn yellow stockings and turkey-cock head-piece, railing against Olivia, Sir Toby, the theatre in general and the audience (us) in particular.

There is audience participation, though. A boy from the audience is invited onto the stage to give him a good kick up the backside, while another couple is commandeered to pull on the rope and kick away the chair while he hangs himself. Lord, how we laughed. He didn’t hang himself, of course, though he told us we could go hang if we wanted.

Friday’s performance happened to be a “signed” one and Crouch worked brilliantly with Sue MacLaine, an actress/writer I have seen elsewhere in her own solo show – as a nude model for a life class; Lucian Freud’s model, in fact, Henrietta Moraes – making sure she underlined his discomfort and shoo-ing her out of the way when distraught, or crossing the stage.

"I'll be revenged on the whole pack of you," is the refrain. It's as though the whole performance is an epilogue to his exit in the play, an extended mutter in the dark, a reflection on what happened - that scrunched up letter is a very sore point - a weighing up of alternatives. His steward's costume hangs on a clothes rack. Will we see him again in his full Puritan, sourpuss glory? Or will he come away, death, and in sad cypress be laid?

It's the most wonderful performance, and I'm intrigued to learn that Crouch is taking it, together with his one-man Dream show, Peaseblossom, to New York. I hope he doesn't get caught up in the hurricane before the theatregoers there are transported in the storm of his own devising.

Before lunch and I Malvolio, I caught Purni’s own 80-minute production of A Winter's Tale, with four fine actors (especially Ben Caplan and Ginny Holder), a limber recounting of the plot that kept the audience of primary school kids pinned to their seats. But what’s this? The statue doesn’t come back to life. The Queen really is dead, and Leontes will just have to live with it.

The lights come up, the scenery is stripped away, the audience invades the stage to mingle with the cast and mess around with the props. This is almost giving deconstruction a good name; you can’t do that at the National Theatre, more’s the pity.