I think the one who asked for a similar type of game should specify in what way he/she means with a similar game.
Stories are all different, which is good, but does he/she maybe mean it in a visual way (render quality / animations / style etc.)
Then Instinct Unleased also has a great visual concept, but a totally different style of art, and then it's a matter of taste if you like it or not.
But you can't compare them visually nor story nor character wise.
If in terms of visual comparision, if you would even try to recommend a sort of similar style/quality, I think Futagenesis Unveiled would come in the same league of renders and animations quality as wel as the futa concept, but again the story is totally different.
Unfortunately that has been abandoned