Firstly I want to throw out that I am not some sort of marketing genius but rather just a fellow coomer who perhaps is more interested in this particular industry than most. Take everything I say with a grain of salt. That being said:
No problem man, it's posts like this that help me narrow my approach and get a better understanding of what I'm dealing here. I suppose I have been cagey about the sexual content in the game, perhaps non-informative is a better word. I will go back to the campaign promise I made when I first started dev for the game: it's a RPG with sex, not a sex game with tacked on RPG elements. I'm banking on the speculation that there is a demand for games with more mature elements, as otherwise this type of experiment essentially alienates both my potential audiences: people looking for sex games don't want to have to actually play a game before they get to the good stuff, and RPG players won't be caught dead playing something labeled a sex game.
Describing it as an RPG first is a good strategy but doesn't necessitate minimizing the erotic aspect in the marketing. I am going to be very vulgar for a second: you are making a product that is designed to capture people's erotic imagination and have them fondle their genitals to orgasm. You are also trying want this product to be otherwise mechanically complex and intellectually engaging, and in a way that hopefully consolidates the roleplaying elements with the dank porn. That is your niche - why shy away from that? Own it. If you were trying to play it safe and thus avoid alienating people like Jinn you wouldn't have set out to make a game with erotic elements in the first place, so surely you are aware that you are blazing a different trail here. Your enthusiasm for the game comes across in the highly informative posts you have written about its mechanics and I think it would project confidence to see the same amount of enthusiasm for the "dark side" of the game, so to speak. I'm not telling you to get obnoxious about it (in a way that a teenager would describe their first sexual encounter or something) but hopefully there is as much to say about the wide variety of intriguing and alluring women you can romance and bed in this game, their personalities, their kinks, what you can do to them and what they can do to you as there is about the game's RPG system.
Thanks for being more informative in this post, though! I guess my main point here is that I find it intuitively true that most people tend to buy into a product's vision when they see its developer demonstrating enthusiasm for it, and that I don't think you should sacrifice it for the sake of trying to straddle a fence between two hypothetical audiences that wouldn't play your game anyway.
I would say Memoirs is more grounded than most people would expect, it's a narrative-first, character-driven game. It's setting is cyberpunk and gritty. That means that sex and the sex trade in general will have a lot of psuedo posthumanist tropes common in cyberpunk (augmentation, AI, cybersex, etc). You won't find the exaggerated proportions or popular fetishes of sex games, because sex in the game operates much like it does in real life: some people have their kinks and some don't. Of course, we're dealing mostly with prostitutes, so expect more than usual. The first optional encounter is with an augmented human and you get to explore some of her built-in gadgets. The second is just a regular flesh-and-blood human, and it gets no kinkier than a bj behind a car.
See, now you are getting to the unique, highly marketable shit! There are not a lot of harem-style cyberpunk porn games out there. You could think that cyberpunk themes would come into play during this game's sex scenes implicitly by the fact that the game takes place in a cyberpunk setting, but there are plenty of games that just use their settings for background flavor and don't capitalize on them. By providing information like this you are helping your potential audience understand what kind of fantasy they will be getting out of this game.
With all due respect, depending on how vanilla it really is, is it wise to label it as a NSFW game in the first place? If you're not really targeting hardcore porn game enthusiast, why not just target the larger non-porn gaming market instead. Take The Witcher 3 for example. There is a ton of adult content and nudity in it, but it's definitely not considered, nor advertised, as a NSFW or Adult Entertainment game.
Hard to say as an observer without knowing just how vanilla "vanilla" actually is.
Of course this question is Tyranicon's to answer, but IMO - yes, it should be labeled an NSFW game. There is a massive difference between games that feature explicit hardcore sex to hopefully make the player pee white and games with softcore erotic components like W3. The former is analogous to porn, the latter to your typical HBO tv show with a sex scene quota.
There are some excellently written full-length porn films (though most of them were produced decades ago) like Barbara Broadcast, yet it would be highly suspect if BB was advertised as a comedy rather than the porno film that it is.