@Samuel_H_Young "Show-don't-tell" is indeed one of the first principles of good writing! It can definitely make things more engaging. I notice you didn't give any examples of showing (as opposed to telling), so for those who aren't familiar, here's one I'm making up right now:
telling: Susan was hungry.
showing: Susan's stomach growled painfully. "I'd kill for a pastrami sandwich," she muttered.
Obviously the second description gives the reader's imagination more to work with. It's also longer, and the extra detail takes more mental processing time.
Let's look at the part of Guenevere you picked:
Arthur orders the circle of guards to step back, and both my father and Morgana come running to my side immediately. Father is angry, and wants to know who's responsible so he can kill them. Morgana is concerned, and looks at my bloodstained sleeve sympathetically.
Arthur calms everyone down and announces that all is well, and the wedding will proceed. His voice is full of confidence and reassurance as he speaks to the crowd.
Here's how I might write that part if I was going more for show than tell (note I'm doing this on the fly and it's not the same quality I might be able to achieve with revision time):
Arthur straightens his back and turns to the guards. "It's all right now," he says. "Stand down." They move away, opening the space around us.
Red-faced and eyes bulging, my father bursts into our midst. "Who's responsible for this outrage?" he demands. "I'll kill them!"
"I assure you, Sir Leodegrance, we'll get to the bottom of this," says Arthur.
Morgana hurries breathlessly to my side. "Are you all right?" she asks me, brows furrowed. Her eyes catch on my healed arm and bloodstained sleeve. "Oh, your dress!"
The assembled crowd is crawling with jittery whispers. Arthur faces them and shouts, "People of Britain! All is well! Someone attempted to disrupt the ceremony, but they were stopped immediately by the heroism of my bravest knight, Sir Lancelot! We will carry on as scheduled, and show the world just how impossible it is to disrupt the happiness of our great nation!"
So the second example never says that Leodegrance is angry or Morgana is concerned; it shows their emotions through their demeanor and their words.
More engaging? Sure, I guess? (Probably more so in the hands of a better wordsmith.)
BUT here's the thing: The first excerpt was 74 words. The second is 143, twice as long. (and I wasn't deliberately trying to make it long; I was just doing my honest best to show instead of telling).
In some cases, the added length of "showing" is 100% worth it. That's especially true in linear fiction, where the reader isn't waiting for a chance to DO anything, but is just wanting to be entertained by the text itself. But even in linear fiction, a writer has to be judicious about adding irrelevant or excessive detail. It's easy to get so bogged down in showing stuff that you never tell an actual story (or your reader jumps ship before you get the chance).
As for interactive fiction: your reader may be enjoying the story, but you're trying to create the illusion that they're in charge. The longer you make the reader wait to do something, the less they'll feel like they have any agency. My own biggest criticism of Guen part 1 is that it's too railroaded -- because of the nature of the story, I can't make it branch a whole lot more than it does (though I am planning to add some more branching if I can).
The wedding scene already has a LOT of pages on which the reader doesn't get to do anything. Even what they can do doesn't make much difference -- sure, you can attack the assassin, but you fail; you can say a few things to a few people, but the wedding basically moves forward the same way no matter what. Most readers seem to find Guenevere's premise and characters interesting enough that they're willing to put up with this lack of agency, but if I DOUBLED the word count by showing instead of telling at every opportunity? Not sure they'd be as willing to ride the linear train.
Of course, one solution would be to add more interactivity, but that means either adding more meaningless flavor choices or adding actual plot changes, and either way it means we spend a lot more time mucking around in the wedding scene, which I honestly think is already pushing the limit in terms of length and reader patience.
If you read Guenevere carefully, you'll find plenty of places where I do "show" in small ways. Arthur goes up stairs two at a time. Lancelot notices Guen's arrival at the camp council and makes sure she has something to eat. Morgana sighs a lot. Merlin has a cheese wheel in his stack of books. In those cases I as the narrator don't outright say "Arthur has lots of physical energy" or "Lancelot is more attentive than Arthur" or "Morgana is frustrated" or "Merlin is weird" -- the details show it (at least, I hope they do).
I'm not saying I couldn't do a better job of this, but I tend to prioritize economy of description. So when I do manage show instead of telling, I'm trying very hard to do it in the most efficient way I can, so that the story is -- as much as I can manage -- about the reader's agency rather than mine.
tl;dr: Show-don't-tell is good advice and well worth thinking about, but sometimes you just need to get to the next thing.