I honestly love all these types, the key is to build anticipation so the player has something to wait for. But right now there's not much of that. I wonder if they do polls about things like these in their patreon when it comes to the next updates. If she is to be fucked by pretty much everyone in this game, i wonder when it's going to start. They could add things like the bartender getting her drunk and fucking her in the ass since the merman has already gone that route. With the dwarves since they already have disguised their cocks hanging out of holes as "worms" they could either get the main dwarf to get a blowjob in a glory hole like scene where he fools Jack into doing it. Or potentially a bukkake like scene where she blows every "worm". The old man in the garden giving her an aprhodisiac potion etc. Honestly there are many things they can do.
The next thing to do would be to give them a different relationship, for example Jack is wary of the perverted bartender and always avoids him, while she trusts immensely the old man, and she isn't aware of the dwarf being perverted. So when each of them progresses it gives a different vibe to the story, and it's not the usual Jack acts like she has 3 brain cells when it comes to sexual acts. While this also changes the role, instead of everyone being a hidden pervert and Jack having the same reaction, it could change into giving them some roles like mentor for the old man and asshole for the bartender and someone who has fallen in love with her like the dwarf etc. Another thing is plot twists, giving those minor characters more thoughts, making them more vocal, giving them ambitions and goals. For example Sam hearing the bartender's plan to put something in Jack's drink in order to fuck her, this gives the bartender more purpose and adds another element. And then there are plot twists like Jack hearing the bartender negotiating buying some aphrodisiac by the old man. Or Sam making a plan where Jack has to seduce or stall a minor character for him to accomplish something and ends up peeping. Or negotiating for something with a minor character and the character in exchange demands a sexual favor from Jack. Those are examples of smaller "quests".
One example now of a big "quest", in the next update Sam wants to fuck Jack, he uses some fake excuse where she's helping him steal some treasure map or magical artifact, whatever, so he has to go to the garden and get an aphrodisiac, use Jack to seduce the old man, get the aphrodisiac, then have Jack stall the bartender with some pretext like to open his safe but instead Sam puts the aphrodisiac in her drink while both Jack and bartender aren't looking, then she drinks it and she wants to fuck and then we have a twist where Sam fails and someone else ends up getting action because something came up. For example the old man saw they stole his aphrodisiac and put something in Sam's drink. One up'ed them all. So when Sam is about to fuck her, the old man gets some action instead. In the inbetween steps in the first part the old man gets action while Jack seduces him, the bartender gets some action while Jack stalls him, she drinks it, bartender wants to take advantage, Sam peeps and when it progresses a bit he "saves her" in order to seem like a hero, Jack is now feeling hot for him, it seems like Sam's plan was a success, she's in full heat, she gives him a blowjob and while Sam was about to fuck her, he feels dizzy and is left on the ground unable to move, and the wise old man who tricked them all comes and fucks her instead. This way we get a cliff hanger and a minor character progresses more instead since we don't want Sam to fuck her yet but Sam also progresses towards fucking her too by getting a blow job. And they keep interchanging between small quests and big quests with multiple parts which leads to main characters getting some action and the minor characters one after another fucking her. Eventually let's say Zombies gang bang Jack and Sam and Cupid dress as zombies too, Cupid gets a blowjob, Sam fucks her in the ass, so when she's having sex already with others, Sam gets some progress gradually to lead eventually in fucking her too from her pussy, as himself, not someone else. An example of a small quest after a big quest which focuses way more on Sam.
This is just one example, but with a structured way they could build up more tension for multiple characters and also variety, slowly progressing by getting steadily more action, and this way people would root for everyone to fuck her, even if they want Sam to fuck her the most, so when the next update comes out, we still have someone else getting action and Sam still peeping when it happens. I'm a writer who has helped some NSFW artists in my free time before with their stories and looking at this game it's obvious they had a good writer at the start. The whole thing was very organised and structured with a clear goal in mind, athough we miss "acts", meaning clear goals of progress, an incident which is defining and causes a change, it feels like this has been stuck in the first act forever. For example the merman fucked her in the ass and nothing changed (plus it happened out of nowhere too). Sam didn't get jealous of someone else fucking her making him eager to fuck her too. Jack didn't get more sexually aroused by what she thought was a "dream" and so on. An example of character progress could be Cupid mastering some succubus arts in order to make Jack horny and Sam finds a magical object instead. They negotiated with someone to give them X if Jack did Y to him? He goes into the room, Jack refuses at the start then Cupid uses his succubus arts. Sam fails to even get a french kiss? He falls into some ancient tomb and finds the golden dildo scepter for example which gets gradually more and more power, so it helps him get progressively more action. So have them fail a few times while minor characters fuck Jack in the 2nd act, and then break it out by giving them something else to evolve and fuck her too in the third act. So this is where it gets tricky for me, for it to have had such structure yet no progress. Till now we had penetration in a dream of Sam and with the merman hypnotizing her, both things eventually had the same impact, one way or another it never happened as far as Jack is concerned so she didn't have to change. It seems like the writer must have been overruled a lot of times, or simply left because there's only so much free time you can have. Otherwise there's no writer and the person making this is good at the intro but bad at the middle, which typically is by far the hardest in writing, so i don't blame him/her, especially if it's an amateur.