If you want to have any hope of having your idea made into a game then at the very least you have to work it quite a bit by designing a "game design document", this document explains the following in detail:
-General overview of the MC and his/her situation
-Lore of the world and anything important to know
-Mechanics and how they are applied into the game
-Main characters of the game
-Content (be it some quests, situations, global events...)
Let's do a fast example shall we?:
Our MC currently lives in the Illadah village, which is under the Holy Empire, after the death of his mother (his last relative alive) decided that it was time to go on an adventure, what will he do in his travels? perhaps he will be just a spectator of the changes? will he take action himself to change things? or perhaps he will be overwhelmed and forced to do things against his will?.
About the lore of the game we would have 3 main religions:
-Holy church: Followers of the goddess of light and equality Allaenah, they believe that each man should have just one woman and that relationships should be proper, albeit they can tolerate people don't following their doctrine there are 3 taboos that they won't:
*Having sex with monsters voluntarely: Monsters are followers of the dark goddess Enarah, created by her corruption of the world, so having sex with those creatures goes directly against the beliefs of the church.
*Having sex with a follower of Illayah: Illayah is the futanari goddess, the myth said that she was the wife of Zehor, both gods were married to each other however Zehor was always having sexual adventures with human women, but one time it became too serious, Zehor fell in love with the female human Henera, seeing the situation Illayah decided to take revenge of both, her revenge towards her husband was to cut off his dick so that he would never be able to cheat again, towards his lover Henera, she decided to fuse the dick of her husband in her body and she would fuck her with the member that so many times had been within her.
But ironically while Illayah was having sex with Henera they fell in love with each other, Illayah then decided that the origin of the sin was on her husband and feeling pleased with the current situation decided to maintain her new dick. Related to Henera she accepted the gift of Illayah and became the first futanari in the world.
*Using evil arts such as mind manipulation to influence other people: Allaenah gave the humans their soul and the evil arts take a direct impact upon it, that's why if discovered anyone that used evil arts will be considered an enemy of the church.
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This is just a bit of an overview and a bit of lore, overall this isn't useful at all because there would be many things to talk about, races of monsters, humanoid races, overall war situation, world events, minor gods, explanation of dark arts and their effects, fight system, important characters...
Don't go with the "I have an idea" if you don't develop it, it is a lot of work but that's what give that idea value.
Look at how the movie industry work. You don't just pitch an idea. You write a whole manuscript and start pass it around to see if someone bite. If someone bite, it usually get re-written dozens of times, before it even might finalize in something.
Yes, this comment is about right.