9 things you need to know about Crystal Maze Special, from new series rumours to what angry Rio Ferdinand is like

The much-anticipated Crystal Maze comeback is on for Sunday, as famous 'n' friendly celeb faces such as Rio Ferdinand, Sara Cox and Michelle Keegan go in search of challenges, crystals and shiny bits of paper in the name of Stand Up To Cancer.

Elongated Extras funnyman Stephen Merchant steps into Richard O'Brien's shoes for the day, and gave a Facebook Live today to answer questions ahead of the weekend's nostalgia explosion - letting some interesting snippets slip in the process…

Related: Here's the first look at the all-new Crystal Maze with Stephen Merchant AND Richard O'Brien

1. It's definitely a one-off

"We haven't discussed it being a series, but for me personally that would be tough. Cos then I'd have to do it all the time, and I'm not sure I'm equipped to be a game show host. I don't think I have that skill set. This was really fun to do, I think I've done quite a good job, you can be the judge of that, but for now this is a one-off edition."

2. The theme tune has been re-recorded with an orchestra

"How about that! No expense spared. Could have just downloaded it from YouTube but no, spent a fortune on an orchestra. That's money that could have gone to Stand Up To Cancer."

3. The Crystal Maze course is much harder than you think

"We filmed it at the recreated Crystal Maze in an office block in north London, where the average Joe can go and play with their mates. It's very difficult. On TV you shout, 'You idiots, that's easy!' at them, but when you're actually there and the clock's ticking, the pressure's on, it's tougher to do.

"I actually went round with some pals, played all the games beforehand, and my chief skill was reaching things down from high up. I was not much good at any of the other stuff."

Related: 12 reasons why we loved The Crystal Maze, from Richard O'Brien to the shoddy prizes

4. Rio Ferdinand struggled the most out of the contestants

"So I wouldn't say anyone did the worst, but I know Rio Ferdinand in one of the games was very frustrated, because obviously he's a sportsman and very competitive, I think he was angry with himself for failing one of the challenges. But he redeemed himself later in the games. So he's been OK - we talked him off the ledge. But they all did well - I'm not just saying that because we didn't pay them."

5. The shaved head was not a Richard O'Brien imitation but a coincidence

"People have asked me if i shaved my head specifically for it - and I am completely bald in the show - but by some amazing coincidence I was shooting a film in America in which I had to shave my head for it. Richard did not give me any personal tips but he does make a cameo."

6. There's no harmonica playing, either

"One of the tricky things when they asked me to do it, was although I had a shaved head, I didn't want to do it like Richard did it. He was very unique and had a very specific and amazing style. He's such an eccentric, charismatic and quirky personality, it seemed weird if I tried to recreate that.

"The harmonica was Richard's - he'd do a merry jig. But 1) I can't play the harmonica and 2) I thought that was a bit of Richard's thing. We pay homage to Richard and Ed Tudor Pole but not try to recreate it just as it was. It was 21 years ago - we've tried to give it our own fresh spin."

7. But Mumsey IS back

"You'll see my interactions with Mumsey, brought to life by the wonderful Maureen Lipman. While I've approached it the way I would do it, we've made some nods to the original, including the Mumsey appearance."

8. Merchant couldn't help keeping a crystal ball - and the outfit

"We were given some commemorative crystals, tiny little ones. But a lot of people ask where they come from on the show, are they made by Swarovski? But you know, they're not - our crystals are actually worth something.

"And I kept the outfit, too. Whenever you do any kind of TV show, if they give you any kind of outfit, always take it. You never know when it might be useful. When you first see me, and I've got the shaved head, you'll probably think it's the Mitchell brother they've got locked up in the attic, and then you see me in the outfit… I mean, it's preposterous, I look like I've arrived in Chitty Chitty Bang Bang. Nevertheless I did keep it - I look like Poldark's flamboyant cousin."

9. Aztec is still the best

"I think we all like the Aztec Zone. One of the most famous zones and a cultural stereotype as well, which we're all big fans of. I'm guessing the viewer doesn't mean erogenous zone - in which case it's the nape of the neck."

The Crystal Maze Stand Up To Cancer special is on Channel 4 this Sunday at 9pm

Stand Up to Cancer is a joint national fundraising campaign from Cancer Research UK and Channel 4 to accelerate new cancer treatments to UK patients and save more lives, more quickly.

Launched in 2012, Stand Up to Cancer's fundraising total has so far reached over £25 million to fund clinical trials across the UK.

To find out how to get involved, visit standuptocancer.org.uk.

Matt Hill

 Matt is a journalist, audience strategist, editorial director and workflow consultant with over 20 years' of experience in the industry.

A former director of audience development and content strategy at Hearst UK, Matt was previously Editor-in-Chief of Digital Spy. There, he contributed features and reviews on TV, movies, consumer technology, video games and Lego sets, won BSME Digital Editor of the Year, and led the team to numerous awards including Campaign Consumer Media Brand of the Year and PPA Digital Content Team of the Year twice.

As Digital Development Director of the Hearst UK portfolio, he oversaw the central digital editorial teams including SEO, video, e-commerce and design, contributing to digital acceleration across all Hearst UK brands from Cosmopolitan to Good Housekeeping.

Before joining Hearst in 2015, Matt edited Future’s consumer technology lifestyle brand T3 and the UK arm of Gawker’s tech culture website Gizmodo, and was deputy editor at ShortList, the then biggest men’s magazine in the UK, interviewing the likes of Quentin Tarantino, Lord Sugar and Sirs Ridley Scott and David Attenborough in the process. LinkedIn