Games where the lewd aspect is actually integrated into the game
Lots of games have some form of split between their gameplay and their lewd contents, showing it as a reward for having completed something unrelated (say box-sliding puzzle games where you unlock 1 new picture for every level you complete), or sometimes even as a reward for when the player fails a task (say games where you get fucked when you lose a battle).
These games might as well just have had their lewd content slapped on after their completion just to try and appeal to another potential market. Instead I desire games where the adult content is actually thought of from the games' conception and a well-integrated part of the gameplay loop.
Some games find a way to center their gameplay around their lewd aspect, be it in the form of sex battles (Karryn's Prison, Light-Space Love), rhythm games that progress their scenes as players progress in the songs (Beat Banger, SpunkStock), character-management games where you control their growth (Akabur's trainer games), or other less generalised ways (Barely Working, Vario Vare, The Imperial Gatekeeper).
Some games also have a gameplay loop centered around their adult content, but with that loop being completely separate from their main gameplay loop used to progress in their story (Unholy Maiden, if you want adult content you can completely ignore dungeon exploration and combat, making the sex stuff feel more like a separate game tacked on than part of the same game)
So I come here seeking more games where there is a lewd content is incorporated into the main gameplay loop, instead of games where either lewd content or gameplay is made into a side-thing that isn't connected to the other.