Review: The London 50 Hour Improvathon (Pleasance Theatre)

Review by Harry Bower

⭐️⭐️⭐️⭐️

Last year, I attended my first ever ‘Improvathon’, the mammoth fifty-hour marathon of improvised comedy performed by a huge cast of performers, directors, technicians, and musicians. After a combined 28 hours of laughing, in my review I wrote that the experience was “every bit as beautifully chaotic, mind-numbingly stupid, unstoppably random and bonkers as you would anticipate it to be”, and vowed to return in 2025 for a second helping of nonsense.

And so here we are, a whole year later, with a new production, a new theme, new and returning performers in a brand new venue. And, as promised, same me, ready to climb onboard this unstoppable improvised train and ride it all the way to the terminus.

If you don’t know, this annual feast of improv is split into two-hour chunks throughout the fifty-hour run time, with each chunk consisting of around an hour and forty minutes of long-form cannon improv, followed by a twenty-minute comfort break for everyone to remind themselves they’re still human. Cleverley labelled ‘episodes’ as part of a ‘tv box set’, each chunk of entertainment is sold separately to guests, who are also able to book night shift, day shift, or weekend passes for a reduced rate.

This year, I decided to do my Improvathon experience a little differently. Instead of sitting for twelve hours at a time, I decided to treat my weekend pass in much the same way ‘normal’ punters would, by dipping in and out regularly for several episodes of the box set at a time, returning to the venue frequently. For the context of this review, I managed four separate trips from Friday through Sunday, for a combined 18 hours of the 50. As with my pitiful 28 hours in 2024, this pales into insignificance when compared with the absolute troopers in the audience who managed to commit their entire weekend to enjoying the journey with the cast and crew. I doff my cap to them all.

By the time I arrived for my first stint, just a couple of hours in, there had already been two murders committed by persons unknown, escalating to include an additional three bodies and a dog by the end of my first episode. From there, things got more eclectic. Weddings, musical numbers, time travel, super heroes, Sigmund Freud, the winter sport ‘Luge’, a sentient ‘Tony the Frosties tiger’ with anger management issues, interactive Dungeons and Dragons… you name it; it’s likely the Improvathon touched on it at some point.

Narratively speaking, it felt as though this year’s ‘thon was poorer than its previous iteration. The ‘Spectacular Spectacular’ theme set in Paris in 1900 is only designed as a framing device and a platform from which the comedy can develop, but the period and subsequent characters, stereotypes and world-building felt restrictive in a way that ‘The Wedding’ theme last year did not. Some cracking name puns (Joe Contraire, Pam au Chocolate, Gordon Bleu, Camden Brasserie, Peter Bread… I could go on) and a particularly amusing stretch in which the director rewards the cast for embracing their 1900s period are the best use of the theme.

There’s only so many times the rich owners of the Roulin Mouge (...) can interact with their staff within the establishment before it becomes narratively boring. One thing you can say about this show - it is never boring or repetitive, but sometimes the unhinged storytelling strays too far away from the long-form continuation of narrative to be fully coherent. Nonsense is fun! But the endless stream of it can shake some episodes from fun to impossible-to-track. 

The sheer number of performers (perhaps too many?) means that it was sometimes literally hours between seeing certain characters reappear in any meaningful way. This made it harder to buy into a character’s narrative arc and really care about their resolution, as I did so much of in last year’s production. Also, given this is live sleep-deprived improvised comedy, there are sensible content warnings on display at the entrance doors. Despite this, it was still occasionally uncomfortable to see a performer stray into grey areas while pursuing a laugh. That risk, I suppose, comes with the unpredictable territory. 

If the whole thing was narratively poorer and less consistent, then technically speaking 2025 felt superior. Well-tested improv games were scattered into almost every episode. Clever and entertaining narrative recaps were shoehorned into the beginning of most episodes to allow people to catch up, beyond a simple character introduction, and it felt as though the direction was allowing for more self-awareness with regard to testing the improvisation of the performers. A sense of ‘meta’ permeated throughout. This vibe shift seemed to up the stakes a bit for the improvisers, and it feels like this delivered some significant peaks and troughs. When paired with crowd favourites like the Women’s Erotic Book Club, the multi-headed dog, and huge Showstopper-esque whole-cast musical numbers, it’s a winning combination.

I am in complete awe of all the creatives participating in this production. To perform or direct (sometimes both) over two full days of improvised comedy must be hard. To do it this well, with this much skill, is a genuinely spectacular feat. Musicians score the entire thing on the fly, lighting operators bathe each scene according to mood or circumstance, and the directors open and close scenes skillfully, maximising laughs and minimising wasted opportunities. When it all works in harmony, it is almost unnoticeable, which is the highest possible compliment I can pay the team. Particularly the musicians - often the perfect score is playing in the background, and it’s pitched so perfectly that you forget it’s a cast of creatives literally deciding in that very moment what note to play next. It is staggeringly effective and impressive.

If you are yet to give the Improvathon a go, but think it sounds up your street, please just book for next year. You might only book one episode or two, but take my advice - don’t fill up your weekend. It’s highly likely you will catch the bug, and your brain will insist you watch many more hours. Surrender to it. In my favourite number this year, the core cast of improvisers are asked to create a song about why they do the Improvathon. Short of “because we’re mad”, the answers given in song form are touching and leave an impression of community and family within the cast. This is a group of objectively hilarious friends getting together once a year to have a laugh with each other. How utterly privileged we are to get to sit and watch them.

The London 50 Hour Improvathon played at Pleasance Theatre on 04-06 April 2025. For more information visit: https://www.improvathon.co.uk/ 

Photos by Claire Bilyard