05/05/2014 13:19 BST | Updated 03/07/2014 06:59 BST

Review: Secret Cinema 21

Secret Cinema has become a "must-attend" event in every Londoner's diary. The 21st edition of the immersive theatre/cinema experience continues it's successful formula of taking over an abandoned building, and filling it with actors.

The premise seems odd: buying tickets to a show when you don't know what it is. In the preceding weeks, emails establish a fictional world and provide details of what to wear. Once there, you get swept up in the atmosphere, as actors talk to you in character, and everyone arrives in their outfits. A different world takes over a part of London for the night.

You enter, are sent to find someone, and the adventure begins. The production is impressive: an entire building decked out in the film's era, dozens of actors doing their utmost to engage you, and set sequences staged around you. With every punter in costume, it's hard to tell who's an actor and who's not, adding to the immersion.

You are left to explore, until a series of events herd the crowd to a hall: it is only then that you discover what the film is - typically a cult classic. As the film progresses, you realise that events and characters encountered through the night were drawn from the film - either directly, or adapted. It's a brilliant concept, and one that works well, with many people returning for show after show.

Whilst the outlying format remains the same, the team tinkers with the formula for each production, with mixed reception from fans. Having been to several, I can offer a few comparisons.

The film choice is always contentious, as it may not be to everyone's taste. With Secret Cinema so popular, it would be tempting to show a well-known film as a crowd pleaser. But cinematic education as part of the experience, and I loved the film on this occasion, all the more so because I would never think to watch it otherwise.

The more you put into Secret Cinema, the more you get out of it, particularly when it comes to discovering hidden rooms and experiences. This reached a peak in the previous production, Brazil. One of my friends complained about the viewing experience there, and I have to admit that I didn't really watch the film, but I enjoyed everything else so much that I didn't mind.

In previous Secret Cinemas there was not just interaction with actors, but things to do with experts and artists: at Prometheus an areologist taught me about Martian rocks; at Shawshank Redemption I learned how to make candles; at Brazil I researched dreams. Either the equivalents weren't there this time, or they were harder to find (let me know if you did find any).

Secret Cinema 21 is still a great night out, with the production impressive, but I'd like them to put back in more activities for next time. Another nice touch might be a little gift as a reward for your discoveries: in one room was a photographer, but you had to pay for the picture. Something as simple as a Polaroid would be a nice memento, particularly with prices reaching £55 with booking fee.

There's a few tickets left for the current show, and my Top-Tip if you attend is to stay around after the film for the full experience.