Hi David,
When it comes to tips for how to get better engagement and discoverability with itch, the consensus seems to be simple: you don't. Itch is a website that's run by a tiny team, who appear to be quite overworked at the moment, and it isn't really clear how, or even if, they are compensated, once you take into account the overhead costs of running it. Discoverability is kind if a crap shoot on here. It's great for hosting things, but it's not really going to go out of its way to drive traffic to any given page - from what I can gather, it shows brand new things on the front page for a few seconds, and then it's a bit of a feedback loop - if you already have a popular game, it's probably going to get top billing, and if not, then it's more or less buried. Using your itch page as a destination and driving traffic to it from elsewhere is probably your safest bet.
As for popular "interactive campaigns with the spark of engagement" or whatnot, to be honest, I am not entirely sure what you mean? Are you writing a campaign / adventure module? If so, my own advice, which is admittedly worth about two cents, would be to ditch all the "marketing speak" and stop worrying about how well your module does in a "focus group." A tabletop rpg module is only as immersive as the GM and the players can make it at the table (or over discord or whatnot), when they're actually playing it, and you will usually not be present for that. You have no control over it. You're also probably not going to sell many copies. If you're designing it for a popular system, like DnD, you might have a chance at a few extra sales, but this is a niche, within a niche, within a niche. And that too is something we have much less control over than we want to believe.
What you do have control over is, well, the module itself, and since the only sane reason to write / design one is for the pure, unadulterated pleasure of doing so, there is no reason for you to be putting anything into it that doesn't, well, "spark joy" ... not for anyone else, but for you. Immersion for the sake of immersion is a moot point. Players might happily ignore that town with the hundred pages of lore and a full population of NPCs, each with a detailed backstory, or might burn it to the ground by accident, or on purpose. And that's ultimately what makes the ttrpg format inherently immersive. I've run a few absolutely bonkers sessions of Honey Heist, some of the most memorable and fun ttrpg experiences in my life, and the entire premise for those fits onto a single page, and most of the "setting" is randomly generated at the start of the game.
If you're writing a campaign setting or module, make it one that you'd want to play. If other people end up playing it, they'll usually be able to tell that it was made with genuine interest and love, even if it is rough around the edges.