I got the perfect kind of game and story. Fair warning, this is a brain dump.
You're the offspring of Lucifer himself. A demonic Nephilim, or in plain terms, half-human, half-demon.
But you're not just any half-demon, no no no. You are Lucifer's spawn. I know technically Lucifer was an archangel and one of the fallen, but whatever. I'll make him the proto demon or something in this game, so that it makes sense.
So as a half-breed, you are tasked by Lucifer himself to take down Lilith.
She's become a fucking feminist because Eve, the first woman, got into her head, and doesn't want to fucking obey anymore. She's rebelled.
That is the story and it's very clever. Why? Because you do not have any demon powers.
You need to suck them dry from Lilith's underlings, which get progressively more powerful, so you can suck more and more demon essence, get more powerful (infinitely, may I add), and eventually take her down.
As for the gameplay, I was initially thinking of a platformer, set some traps, have some enemies, regular stuff. But I felt that was meh.
SO. I came up with something different. I would love a game like Demon Girl Gauntlet mode (basically infinite mode, but it gets harder and harder).
Now the way I imagine this works is that it won't actually be infinite mode. You'll have both a Story Mode and a "roaming/exploring" mode so that you can get stronger. You'll have the same character, but you do need a way to get stronger.
How do you get stronger? Well, make. them. cum. You gotta have make every single demon submit.
I am thinking of a way to have this with some dom/sub play but it's too early to think about that. The point is that you gotta make them cum. The point of the game IS TO HAVE SEX. And then you absorb some demon power and are free to allocate it to your stats.
NOW. What happens if you cum first? It would be a shame to be game over, right?
I was thinking of a mechanic in which the hornier you are and closer to climax, you get more powerful. But if you somehow lose, you lose 10% of your max health or something like that. When you're out of health normally, you're just beaten into submission, and can't resist getting fucked or can't pleasure your enemies (idea is WIP).
Here comes the fun part. The demon you lose fully to (or demons, I am thinking group sex animations - I love those), get 6.66x times more powerful. (would've loved to have pure 666x but that would be too op and you need to grind too much). You can then go explore up until that point where you encounter THE DEMON that you lost to. And you need to beat it to move forward. Ofc, you can always escape and restart, so that you can reach that demon and level up in the meantime. Maybe I'll make you lose stats too, so that you try NOT to lose. Just don't cum too much, mkay?
I'd also love a skill tree here. The programming part is the easiest. I'll have a tougher time with the art.
But that's why I'd like one flat endless level. No level design == more fucking animations.
As for Story Mode, the end game is:
1. Beat Eve. The first woman.
2. Beat Eve + minions.
3. Beat Lilith. The first female demon. (technically she's the first woman, but whatever; it's fantasy, so I'll change the lore)
4. Beat Lilith + minions.
5. Beat both at the same time.
6. Beath both + minions.
This game, if it ever comes into existence, will be so fucking fun and hot (for myself anyway)!
Everything here is subject to change ofc. This are just some ideas I had when I was trying to sleep.
Any questions are welcome and I'll do my best to follow up and reply.