(Spoilers follow, although I'd be surprised if anyone's reading this who hasn't seen the film yet!)
"Back to the Future" is one of my favourite films, so I'm always happy to watch it again. It struck me as odd timing to show this film last year, rather than waiting for the 30th anniversary this year, but then I realised that it was probably a long term plan: they could show "Back to the Future part II" in 2015 (so that the real date would match the date within the film), and then maybe show "Back to the Future part III" in 2016. However, if that was their plan, it didn't work out; they showed "Star Wars: The Empire Strikes Back" this summer instead.
That in turn is probably down to all the controversy surrounding last year's event. The organisers cancelled the opening night at very short notice, just 90 minutes before it was due to open when the people with tickets were already on their way there. Then the organisers cancelled the following 3 nights as well, and it eventually opened about a week late. The Guardian wrote about it at the time:
Great Scott! Secret Cinema's Back to the Future opening night cancelled
Back to the Future: thousands still hoping to see Secret Cinema production
According to the rumour mill, this was because the council weren't happy with the safety arrangements (e.g. fire exits), but I don't know how true that is.
Anyway, this didn't directly affect me, and the organisers had sorted out these problems by the time I went along. They sent out several emails in the run-up to the event, to the extent that I struggled to keep up. The basic idea was to recreate 1955 Hill Valley (particularly the town square), so it seemed a bit like a LARP event: everyone was asked to dress in 1950s clothing, and I was given a name/occupation so that I could print out fake business cards: Myron Diaz, Barn Worker.
The organisers also asked people to bring along particular items with them, e.g. a pair of sunglasses, a stopwatch, and a family photo. As it turned out, I didn't need any of those things, so I think the concept may have just been leftover from the company's origins; if you didn't know which film you were going to see, that would give you a clue, but in this case they were irrelevant.
The event was held at the Olympic Park in east London. When I arrived, the check-in process was a bit more elaborate than most cinemas. They inspected my ticket, but they also searched everyone's bags for any forbidden items. In particular, you weren't allowed to take cameras or mobile phones inside. I can understand why they didn't want people taking photos, and I think it's good when people actually look at what's happening in front of them rather than watching it second-hand through a tiny screen; this also meant that there wasn't a sea of raised arms holding phones whenever something significant happened nearby. I chose to leave my phone at home, rather than handing it in at the desk and collecting it afterwards, although that was a minor inconvenience (i.e. I didn't have it for the rest of the day). I think this also contributed to some of the bad feeling when the opening night was cancelled, and the cancellation was announced on Twitter: the organisers told people not to bring phones, then sent out a message which you would only see if you had a phone with you!
The other restriction was that you weren't allowed to take any food or drink inside. As far as I can tell, this wasn't a security issue (unlike airlines), it was just that they wanted you to buy stuff from their vendors. The food prices weren't too bad by London standards, and they had a lot of vegetarian options, e.g. £6 for a veggie burger or £5 for a Quorn hotdog. I thought it was a bit harsh that we weren't even allowed to take in water with us, especially since I didn't see anyone selling water inside (or any free taps); Pepsi cost £3 for a 330ml can, which was a bit more exorbitant than the food prices. Fortunately it wasn't a very hot day, so there was no risk of dehydration.
Once I'd checked in, I had a while to explore before the film started. I walked past various houses on my way up the hill, which I recognised from the film, e.g. Marty's parents' (well, grandparents') homes and Biff Tannen's house with the "Keep out!" signs in the garden. This is where I got a bit confused by the concept, although in hindsight I was probably overthinking it. Putting this in LARP terms, was I supposed to be IC (in character) or OC (out of character)? Thinking about my fake identity as Myron, it would be rude for me to go barging into someone else's house, so I didn't do it. On the other hand, if this was a museum then they'd expect visitors to look around, and I saw several other people going inside; in a similar way, when I visited the ruins of Pompeii, I didn't feel guilty about standing in (what used to be) someone else's villa.
There's a photo album on Flickr which shows some of the buildings in the main square. They'd certainly made an effort there, e.g. the corridor of the high school had a bunch of lockers with posters and flyers stuck to doors. They also had a comic shop, although I'd nitpick by saying that the covers on the wall were all too modern for 1955. (For instance, most of the recognisable Marvel superheroes started in the 1960s.) There were a few actors dressed up as characters from the film, e.g. "Marty" was asking people whether they'd seen George McFly, and Doc Brown enlisted people to help out with science experiments, so that was a nice touch.
There was a grass (astroturf) area in the middle of the square, and that's where everyone sat to watch the film. The clock tower was on top of a building which took up one side of the square, and they used that as the cinema screen. I didn't take a cushion/blanket, and I was fine sitting on the ground for a couple of hours, but your level of comfort probably depends what you're used to. I sat right at the back, on the edge of the lawn; that meant that I had a slightly impaired view of the screen, but I had a better view when stuff was happening outside.
That leads onto the main attraction: there was a "shadow cast" who mirrored key parts of the film. For instance, there's a scene (in 1955) where Biff's gang chase Marty around the town square in their car; he's on an improvised skateboard, and he hangs onto the back of another car. The cast recreated that, by having the cars driving around the square around the audience. (I suspect this was one of the safety issues which postponed opening night; there were staff on duty to stop anyone running out in front of the oncoming vehicles, and they drove at a fairly sedate pace.) The organisers also had a DeLorean and they drove that around the square too. There's a very short video on Facebook which shows a few highlights, including Doc Brown sliding down the wire from the clock tower near the climax of the film.
On a related note, I mentioned that the weather wasn't very hot that night. In fact, we got a bit of wind near the end of the film; it didn't rain, but this mirrored the storm on the screen quite nicely, and that's a benefit to watching the film outdoors.
Overall, I enjoyed the evening. I'm not sure whether it was really worth the cost (£55), but I've paid similar prices for West End theatre trips a couple of times. I probably won't go to any more of their events, but I don't regret going to this one; I'd be interested to hear from people who've been to other Secret Cinema events, to see how they thought this one compared.