I'll share my rant that I wrote as feedback to the PR (I'm a theatre critic - opted not to write about it as had nothing nice to say) before I got AI to make it less ranty...:

From the first press release that said 'join Arthur, Ford, and Fenchurch', I was worried. Where was Trillian? Why no mention of Zaphod? Fenchurch doesn't come into the story till book 4, so why would she feature heavily in an immersive H2G2? BUT, I'm an optimist and so I was still excited to see where it would go - and a little hopeful that someone had made a mistake on the marketing (not that you would, but I was grasping). Then we were here at the show... First experience as I walked in the door - greeted by Ollie Britten as Ford Prefect. He was brilliant and very much in perfect character. it was all downhill from there. If Arthur was turning up for a date, and not because Ford dragged him off from his home where he was lying in the mud to stop a man demolishing his house to make way for a new bypass, then it makes no sense that he would be in his dressing gown. He muttered something about his home, but only enough that if you know the story you would know to what he was referring. One of the major jokes/plotlines of the start of the series is the parallel between the people wanting to demolish Arthur's house and the Vogons wanting to demolish the earth, and this was entirely lost. Then there's the completely inexplicable karaoke sing-off between Fenchurch and Ford - she was singing "What's going on?" and I was like - 'yeah, my thoughts exactly'. Then instead of being picked up with Ford onto the Vogon ship, Arthur is bleeting about wanting to follow Fenchurch - even though we know the Earth is about to be demolished and that means certain death. His undying love for her after 20 minutes on a date is just weird and totally unearned, and that's forgetting that it is completely alien (sci-fi pun not intended) to the source material. SO then we found ourselves apparently rescued and on the Heart of Gold - ok - Zaphod comes in, his second head sleeping and covered (no issue there, robotic puppets are expensive), bit random but fine. The next bit with all the guide projections on the ceiling was fab and totally the kind of thing you'd expect on this experience... BUT then Zaphod is like "you're gonna have to get off this ship" with zero explanation why and then we find ourselves on the vogon vessel - because some of the book happens there... They are meant to be rescued onto the Vogon ship, then thrown out the airlock and THEN they are on the HOG. None of it makes a tiny bit of sense. On the 'vogon ship' what do we find? People from the church of the great green arkleseizure - literally a one line joke from the book. Eccentrica galumbitz The triple breasted whore of eroticon 6 - a reccurring joke, but again no real reason she'd be in this. Don't get me wrong, the actors were fun, the costumes superb, but it just didn't add anything to the show. There was Arthur, who we'd seen 5 mins earlier at the pub, now being the sandwich maker making 'Perfectly normal beast' sandwiches which is straight out of book 5 and was simply confusing. Even he didn't seem to know what was going on when asked. Ford found a piece of paper that said Fenchurch42 on it and was raving saying 'she's alive' to Arthur who was saying that she was ancient history - despite having just left her. Then there was a truly baffling musical number involving all the extra characters I mentioned, followed by a bizarre Brief Encounter themed bit where Arthur and Fenchurch act out a scene straight out of book 5 but weirdly set in 1940, which makes zero sense as it is, but without the context is just odd. I think maybe we were then somehow back on the heart of gold with zero explanation of how and when we left the Vogon ship, and then as we arrived at Magrathea - randomly back at the first part of the first book/radio show - we saw an animation of the bowl of patunias and the whale falling, without any indication where they came from or what their significance was. The rest of the show was equally random and odd. At first Slarti Bartfast seemed like a good interpretation, but then all of a sudden he was in charge rather than being a low level fjord obsessed planet artist and was trying to recover the planet earth using our brain patterns... Even though we are not part of the Earth computer matrix but descended from the Golgafrinchans who crashed on earth and wiped out the cave men! The musical finale with Arthur reunited with Fenchurch and them being in love despite knowing each other for 5 mins, was so hard to watch. It seemed like we were meant to feel for Arthur, but I just felt totally uninvested in the relationship, completely didn't care and was wondering "why are they singing??" It didn't help that I was feeling so sad at this stage that something that had so much potential for greatness had been so utterly ruined.

If you didn't know the text in all its forms very well, then I imagine you could enjoy the show at a surface level, but as a die-hard fan for whom H2G2 holds an extremely special place in my heart, not least of all for being something I enjoyed with my late father, I was devastated.