After thinking it about it overnight, I think, Bad Idea, that you might not be able to craft a GOOD game with the requirements you’ve listed. The problem is game length.
VERY short “sex featuring” games don’t have time to do anything but show you the naked and do whatever it is they might do with the sex. For a short 10 to 20 minute puzzler, look at the various “sextris” titles out there. It’s Tetris, but using people as the pieces. Occasionally, when you put the right posed girl with the right posed boy, there’s a vey small animation of them doing it, then BAM! The pieces are gone. Various combinations of poses create such sex matches, and it can be as varied as the creators want to allow (so you can end up having a huge orgy of many pieces at once— if the developer decided that was worth coding in). Several of these that I’ve seen will have “levels”, where after getting enough matches, the screen clears, you see a model from a strip pictorial series and you move on to the next level. The “reward” of the game is that the further you progress in levels, the more naked the model gets until you get a final very naked and very posed shot showing off of the gal. (Although games where they’ve allowed for creative matches in pieces can also be a reward to the player for finding them— adding another challenge and reward in the game.)
In fact, most casual play puzzlers will use that “a girl gets more naked” as the reward for progressing. Whether it’s a breakout style game (with the bricks covering the picture), or a reversed Qix (where the areas you cover/capture REVEAL the masked picture), those all use that same reward mechanism.
In other short sex games, all you end up with is a sex doll doing what you tell her or responding to being used/manipulated (the make the girl feel good). Since the girl is ALREADY the reward for the player, there isn’t any real game play in those. Sometimes, you will find one where there’s a mechanism where you have levels, such that by making a gal experience a certain amount of stimulus, you get to the next level, and she’s posed more openly/vulnerability, and you have more options on how to use/command/manipulate her. That can be a “training a sex slave” or “seducing the gal” styled game— and in this case, the reward for playing more is you get more ways to play with the gal. Those are slightly more fun to PLAY, as there is the growing or continuing “rewards” for playing and achieving the goal.
And that is what MOST such games are missing. Games are fun for their experience, their challenge, and their rewards. Most of the bishojo games sold by Peach Princess fall into the high experience (graphics, music, and narrative), low challenge (make a few choices/clicks), and low to moderate reward (low- erotic graphics, moderate- emotional satisfaction from formed connections from experiences). You’ll notice it is the narratives, allowing players to form some mental connection (emotonal mainly), that are the primary mechanism that creates the heigher rewards for playing the game (normally you’d call it winning, but often a BAD END (Lose game) can give the player an excellent experience, and therefore an excellent emotional reward, as may even heighten their sense of reward as their understand what happens when they fail to achieve their goal).
Very short sex based games just don’t have the time to allow that player to form significant connections to the game, which is why they are basically “flat”. Either you enjoy shoving various objects into a person’s orifices, or you don’t. Either you enjoy a game where you beat a person’s ass with various implements, or you don’t. For the darker tastes, Either you enjoy a game where you pour hot metal into various orifices (natural and those you make) of the torture viction, or you don’t. But the game is “flat”, because there’s no reward cycle, theres no extending that experience (with new ones) in that world construct, and there is no emotional connection or growing emotional investment.
So you project, whatever it is, will be highly limited by the game length you are going to provide. Anything under 2 hours play length is going to be extremly challenging. Anything under 30 minutes will just be a “slap that ass, poke that hole” or some puzzle that’s been “sexified”, I think, and those are usually only interesting for a shorter time than the available game play. Otherwise, you’d be able to do 1 extended sex scene (a narrative or a direct the sex doll(s)), and you seem to be out to not do a narrative.
So, what have I missed and what have I gotten completely wrong for what you are doing?
Remember, sex is a fairly empty experience without emotional content and context. Your own complaints about eroge games you’ve tried (and your own complaints with the “bad” games on that site you are wanting to get money from), show that you understand that. What you complain about not understanding is a complaint about not having any handles for you to mentally latch onto, so you can get the full reward experience for getting the preacher’s daughter to stand on her hands and wrap her ankles around your neck. You just don’t connect to that character, so the “progress” of the relationship or that “reward” for pursuing her just has no meaning or value to you. As someone that’s played several eroge games, that happens to all of us. If you want a good game to play, go over to the main forum and ask about suggestions for games to play— and tell people what you like. That’s why many of us come here and talk with each other. To help get turned on to games we can connect with, and therefore maximize our enjoyment.