(SPOILERS IN REVIEW)
There are very few games, in my opinion, quite like Absolutely Perfect Specimen. 

Sure, plenty of games use the format of "seemingly cute game that gradually gets darker", but Absolutely Perfect Specimen sticks out in my mind as the most impactful in how it uses that transition from sweetness to wrongness. The way the sweetness and blissfulness of Pan and Amy's relationship gradually crumbles away is masterful. The fluffy idealized sex scenes become nauseatingly realistic and deeply uncomfortable. The way Pan and Amy's relationship begins to break down as Amy neglects her more and more (expecting her to still love her) and as Pan finds out the truth was so intriguing to watch. And, lastly, the way the whole maid/master dynamic and Pan's dependency on Amy is completely recontextualized by the end of it is masterful writing, in my opinion.
And as for how it made me feel, personally? As a trans woman who has experienced similar things to this, it felt both heartwrenching and horrifying. The bit where Pan(/Nikki) talked about the doll-like standard of femininity enforced upon women like herself hit me in a deep spot that no other game really has been able to.