That about sums up this game concept. The storyline is a family, probably heavy on females, out for a camping trip. Everything is normal one moment...then, they find themselves elsewhere. "Elsewhere" is an alternate dimension that they discover all too quickly is full of nasty humanoids and other creatures. Rather than focusing on blood and guts, the local denizens have (mostly) breeding on the mind. This does not preclude violence and conflict by any means, but most of where you would expect to find blood and gore were this a horror movie, you'll find NC sex instead.
Of course, there'll be a larger plotline. The family will discover they're not the first humans to find themselves there. And this alternate world holds some secrets, ones with a bearing on Earth itself.
I'm picturing the storyline being about 30% hardcore sex and horror, 30% role-playing, 30% mystery solving and discovery, and 10% sheer fantasy/sci-fi--and just a dash of camp tossed in for fun. This will be freeform. I will use dice when they are occasioned, but I'm not envisioning frequent dice-tossing here. Note that I tend as a GM to not serve up stories on a silver platter. That is to say, you will need to actively seek clues, explore, do things, take actions, and so forth if you want to get the most out of this game. Possible story-arcs and sub-adventures will be presented, but I have never believed in linear, forced storylines. What you do in this world is up to you.
As per my own personal quirks and counter-quirks, sex in my stories tends to be straight, and to involve dominant males and neutral or moderately submissive females. This isn't to say other forms of sex are verboten, but if you're looking for homosexuality it probably won't come from me/my NPCs. Ditto for D/s scenes with a domme. Just not my cup of tea. But if it happens between PCs, it's fine with me.
As for your characters, I'm looking for a normal, everyday human family and friends of said family. Your characters do not begin with any special powers, nor are they über-spies or hardcore survivalists. I may open the game to people wishing to play denizens of the alternate universe, but that will be after the storyline has gotten underway. You the players are free to negotiate with each other what the family and friends consist of, what relationships you have, and so forth. (I think this is better than me posting a template of characters and asking people to claim one.)